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# Copyright (C) 2011 Nils Liberg (mail: kotorinl at yahoo.co.uk) | |
# | |
# This program is free software: you can redistribute it and/or modify | |
# it under the terms of the GNU Lesser General Public License as published by | |
# the Free Software Foundation, either version 3 of the License, or | |
# (at your option) any later version. | |
# | |
# This program is distributed in the hope that it will be useful, | |
# but WITHOUT ANY WARRANTY; without even the implied warranty of | |
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
# GNU Lesser General Public License for more details. | |
# | |
# You should have received a copy of the GNU Lesser General Public License | |
# along with this program. If not, see <http://www.gnu.org/licenses/>. | |
from fractions import Fraction | |
key_data = \ | |
{'c': ('#', 0), 'am': ('#', 0), 'ddor': ('#', 0), | |
'f': ('b', 1), 'dm': ('b', 1), 'gdor': ('#', 1), | |
'bb': ('b', 2), 'gm': ('b', 2), 'cdor': ('#', 2), | |
'eb': ('b', 3), 'cm': ('b', 3), 'bbdor': ('#', 3), | |
'ab': ('b', 4), 'fm': ('b', 4), 'ebdor': ('#', 4), | |
'db': ('b', 5), 'bbm': ('b', 5), 'abdor': ('#', 5), | |
'gb': ('b', 6), 'ebm': ('b', 6), 'abdor': ('#', 6), | |
'cb': ('b', 7), 'abm': ('b', 7), 'dbdor': ('#', 7), | |
'g': ('#', 1), 'em': ('#', 1), 'ador': ('#', 0), | |
'd': ('#', 2), 'bm': ('#', 2), 'edor': ('#', 0), | |
'a': ('#', 3), 'f#m': ('#', 3), 'bdor': ('#', 0), | |
'e': ('#', 4), 'c#m': ('#', 4), 'f#dor': ('#', 0), | |
'b': ('#', 5), 'g#m': ('#', 5), 'c#dor': ('#', 0), | |
'f#': ('#', 6), 'd#m': ('#', 6), 'g#dor': ('#', 0), | |
'c#': ('#', 7), 'a#m': ('#', 7), 'c#dor': ('#', 0), } | |
def get_base_note_for_key(key): | |
key = key[:2] | |
# print key, notes_sharp, notes_flat | |
if key in notes_sharp: | |
return notes_sharp.index(key) | |
if key in notes_flat: | |
return notes_flat.index(key) | |
key = key[:1] | |
if key in notes_sharp: | |
return notes_sharp.index(key) | |
if key in notes_flat: | |
return notes_flat.index(key) | |
raise Exception("error, incorrect key:%s" % key) | |
def get_best_key_for_midi_notes(notes): | |
notes = [n % 12 for n in notes] | |
penalty_key_tuples = [] | |
for key in key_data: | |
accidentals = get_accidentals_for_key(key) | |
basic_notes_in_key = [x+y for x, | |
y in zip(doremi2chromatic, accidentals)] | |
penalty = len( | |
[note for note in notes if not note in basic_notes_in_key]) | |
if notes[-1] != get_base_note_for_key(key): | |
penalty += 2 | |
if key.endswith('dor'): | |
penalty += 1 | |
penalty_key_tuples.append((penalty, key)) | |
penalty_key_tuples.sort() | |
# print '\n'.join((str(x) for x in penalty_key_tuples)) | |
# print 'notes[-1]=', notes[-1] | |
# print 'penalty', penalty_key_tuples[0][0] | |
return penalty_key_tuples[0][1] # key of the first (and best) item | |
def update_extra_accidentals_for_note(basic_accidentals, extra_accidentals, note): | |
# merge the basic and extra accidentals and let the later have precedence over the former | |
accidentals = [b if b is not None else a for a, | |
b in zip(basic_accidentals, extra_accidentals)] | |
basic_notes_in_key = [x+y for x, | |
y in zip(doremi2chromatic, basic_accidentals)] | |
current_notes_in_key = [x+y for x, y in zip(doremi2chromatic, accidentals)] | |
change = None | |
# if not note in current_notes_in_key: | |
# if | |
return {None: '', | |
0: '=', | |
-1: '_', | |
1: '^'}[change] | |
# map from do-re-mi scale index to chromatic interval | |
doremi2chromatic = [0, 2, 4, 5, 7, 9, 11, 13] | |
# map from note name to note number in a C scale | |
note2number = 'cdefgab' | |
notes_sharp = 'c c# d d# e f f# g g# a a# b'.split() | |
notes_flat = 'c db d eb e f gb g ab a bb b'.split() | |
def get_accidentals(fifths): | |
# determine the accidentals for one octave | |
steps = 'C D E F G A B'.split() | |
one_octave = [0] * 7 | |
if fifths > 0: | |
for i in range(fifths): | |
one_octave[(3 + i*4) % 7] = 1 | |
else: | |
for i in range(fifths+1, 1): | |
one_octave[(6 + i*4) % 7] = -1 | |
scale = [] | |
for i in range(7): | |
scale.append(steps[i] + {-1: 'b', 0: '', 1: '#'}[one_octave[i]]) | |
print(' '.join(scale)) | |
# use the same for all octaves | |
accidentals = {} | |
for octave in range(1, 7): | |
for step in range(7): | |
note = '%s%s' % (steps[step], octave) # eg. G4 | |
accidentals[note] = one_octave[step] | |
return accidentals | |
def get_accidentals_for_key(key): | |
''' returns a list of seven values corresponding to the notes in the C scale. 1 means #, -1 means b, and 0 means no change. ''' | |
key = key.lower().strip().strip() | |
sharp_or_flat, number = key_data[key] | |
# initially no of the seven notes are flat or sharp (0=neutral) | |
accidentals = [0] * 7 | |
# add accidentals | |
for i in range(number): | |
if sharp_or_flat == '#': | |
accidentals[(3 - 3*i) % 7] = 1 | |
else: | |
accidentals[(6 + 3*i) % 7] = -1 | |
return accidentals | |
class Note: | |
def __init__(self, note, duration, ties_to_next=False, broken_rythm=''): | |
self.note = note # number of semitones from centre note | |
self.duration = duration # duration expressed as a Fraction object | |
# whether the abc representation of this note ended with '-' representing a tie to the next note | |
self.ties_to_next = ties_to_next | |
self.broken_rythm = broken_rythm # the ABC broken rythm symbol or an empty string | |
# (used when the duration of the next note is established) | |
def __repr__(self): | |
''' returns a string representation of this Note object ''' | |
notes = ('c', 'c#', 'd', 'd#', 'e', 'f', | |
'f#', 'g', 'g#', 'a', 'a#', 'b') | |
n = notes[self.note % 12].upper() | |
octave = self.note / 12 | |
if octave > 0: | |
if octave >= 1: | |
n = n.lower() | |
if octave > 1: | |
n = n + "'" * (octave - 1) | |
elif octave < 0: | |
if abs(octave) > 1: | |
n = n + "," * abs(octave) | |
return n # + str(self.duration) | |
def __str__(self): | |
return repr(self) | |
# print get_best_key_for_midi_notes([0, 2, 4, 6, 6, 6, 7, 0]) | |
# print get_base_note_for_key('c') | |