def augment(self, ns):
stretch_factor = gauss(1.0, 0.5)
velocity_factor = gauss(1.0, 0.2)
transpose = randrange(-5, 7)
ns = stretch_note_sequence(ns, stretch_factor)
for note in ns.notes:
note.velocity = max(1,
min(127, int(note.velocity * velocity_factor)))
return transpose_note_sequence(ns, transpose, in_place=True)[0]
def testStretchPipeline(self):
note_sequence = common_testing_lib.parse_test_proto(
music_pb2.NoteSequence, """
time_signatures: {
time: 1.0
numerator: 4
denominator: 4}
tempos: {
qpm: 60}""")
testing_lib.add_track_to_sequence(note_sequence, 0,
[(11, 55, 0.22, 0.50),
(40, 45, 2.50, 3.50),
(55, 120, 4.0, 4.01)])
expected_sequences = [
sequences_lib.stretch_note_sequence(note_sequence, 0.5),
sequences_lib.stretch_note_sequence(note_sequence, 1.0),
sequences_lib.stretch_note_sequence(note_sequence, 1.5)
]
unit = note_sequence_pipelines.StretchPipeline(
stretch_factors=[0.5, 1.0, 1.5])
self._unit_transform_test(unit, note_sequence, expected_sequences)
def augment_note_sequence(ns, stretch_factor, transpose_amount):
"""Augment a NoteSequence by time stretch and pitch transposition."""
augmented_ns = sequences_lib.stretch_note_sequence(
ns, stretch_factor, in_place=False)
try:
_, num_deleted_notes = sequences_lib.transpose_note_sequence(
augmented_ns, transpose_amount,
min_allowed_pitch=MIN_PITCH, max_allowed_pitch=MAX_PITCH,
in_place=True)
except chord_symbols_lib.ChordSymbolError:
raise datagen_beam.DataAugmentationError(
'Transposition of chord symbol(s) failed.')
if num_deleted_notes:
raise datagen_beam.DataAugmentationError(
'Transposition caused out-of-range pitch(es).')
return augmented_ns
def transform(self, note_sequence):
return [
sequences_lib.stretch_note_sequence(note_sequence, stretch_factor)
for stretch_factor in self._stretch_factors
]
def transform(self, input_object):
note_sequence = input_object
return [sequences_lib.stretch_note_sequence(note_sequence, stretch_factor)
for stretch_factor in self._stretch_factors]
