def process_record(wav_data,
ns,
example_id,
min_length=5,
max_length=20,
sample_rate=16000,
allow_empty_notesequence=False,
load_audio_with_librosa=False):
"""Split a record into chunks and create an example proto.
To use the full length audio and notesequence, set min_length=0 and
max_length=-1.
Args:
wav_data: audio data in WAV format.
ns: corresponding NoteSequence.
example_id: id for the example proto
min_length: minimum length in seconds for audio chunks.
max_length: maximum length in seconds for audio chunks.
sample_rate: desired audio sample rate.
allow_empty_notesequence: whether an empty NoteSequence is allowed.
load_audio_with_librosa: Use librosa for sampling. Works with 24-bit wavs.
Yields:
Example protos.
"""
try:
if load_audio_with_librosa:
samples = audio_io.wav_data_to_samples_librosa(wav_data, sample_rate)
else:
samples = audio_io.wav_data_to_samples(wav_data, sample_rate)
except audio_io.AudioIOReadError as e:
print('Exception %s', e)
return
samples = librosa.util.normalize(samples, norm=np.inf)
# Add padding to samples if notesequence is longer.
pad_to_samples = int(math.ceil(ns.total_time * sample_rate))
padding_needed = pad_to_samples - samples.shape[0]
if padding_needed > 5 * sample_rate:
raise ValueError(
'Would have padded {} more than 5 seconds to match note sequence total '
'time. ({} original samples, {} sample rate, {} sample seconds, '
'{} sequence seconds) This likely indicates a problem with the source '
'data.'.format(
example_id, samples.shape[0], sample_rate,
samples.shape[0] / sample_rate, ns.total_time))
samples = np.pad(samples, (0, max(0, padding_needed)), 'constant')
if max_length == min_length:
splits = np.arange(0, ns.total_time, max_length)
elif max_length > 0:
splits = find_split_points(ns, samples, sample_rate, min_length, max_length)
else:
splits = [0, ns.total_time]
velocity_range = velocity_range_from_sequence(ns)
for start, end in zip(splits[:-1], splits[1:]):
if end - start < min_length:
continue
if start == 0 and end == ns.total_time:
new_ns = ns
else:
new_ns = sequences_lib.extract_subsequence(ns, start, end)
if not new_ns.notes and not allow_empty_notesequence:
tf.logging.warning('skipping empty sequence')
continue
if start == 0 and end == ns.total_time:
new_samples = samples
else:
# the resampling that happen in crop_wav_data is really slow
# and we've already done it once, avoid doing it twice
new_samples = audio_io.crop_samples(samples, sample_rate, start,
end - start)
new_wav_data = audio_io.samples_to_wav_data(new_samples, sample_rate)
yield create_example(
example_id, new_ns, new_wav_data, velocity_range=velocity_range)
def process(self, kv):
# Seed random number generator based on key so that hop times are
# deterministic.
key, ns_str = kv
m = hashlib.md5(key.encode('utf-8'))
random.seed(int(m.hexdigest(), 16))
# Deserialize NoteSequence proto.
ns = note_seq.NoteSequence.FromString(ns_str)
# Apply sustain pedal.
ns = sequences_lib.apply_sustain_control_changes(ns)
# Remove control changes as there are potentially a lot of them and they are
# no longer needed.
del ns.control_changes[:]
if (self._min_hop_size_seconds
and ns.total_time < self._min_hop_size_seconds):
Metrics.counter('extract_examples', 'sequence_too_short').inc()
return
sequences = []
for _ in range(self._num_replications):
if self._max_hop_size_seconds:
if self._max_hop_size_seconds == self._min_hop_size_seconds:
# Split using fixed hop size.
sequences += sequences_lib.split_note_sequence(
ns, self._max_hop_size_seconds)
else:
# Sample random hop positions such that each segment size is within
# the specified range.
hop_times = [0.0]
while hop_times[
-1] <= ns.total_time - self._min_hop_size_seconds:
if hop_times[
-1] + self._max_hop_size_seconds < ns.total_time:
# It's important that we get a valid hop size here, since the
# remainder of the sequence is too long.
max_offset = min(
self._max_hop_size_seconds, ns.total_time -
self._min_hop_size_seconds - hop_times[-1])
else:
# It's okay if the next hop time is invalid (in which case we'll
# just stop).
max_offset = self._max_hop_size_seconds
offset = random.uniform(self._min_hop_size_seconds,
max_offset)
hop_times.append(hop_times[-1] + offset)
# Split at the chosen hop times (ignoring zero and the final invalid
# time).
sequences += sequences_lib.split_note_sequence(
ns, hop_times[1:-1])
else:
sequences += [ns]
for performance_sequence in sequences:
if self._encode_score_fns:
# We need to extract a score.
if not self._absolute_timing:
# Beats are required to extract a score with metric timing.
beats = [
ta for ta in performance_sequence.text_annotations
if ta.annotation_type == BEAT
and ta.time <= performance_sequence.total_time
]
if len(beats) < 2:
Metrics.counter('extract_examples',
'not_enough_beats').inc()
continue
# Ensure the sequence starts and ends on a beat.
performance_sequence = sequences_lib.extract_subsequence(
performance_sequence,
start_time=min(beat.time for beat in beats),
end_time=max(beat.time for beat in beats))
# Infer beat-aligned chords (only for relative timing).
try:
chord_inference.infer_chords_for_sequence(
performance_sequence,
chord_change_prob=0.25,
chord_note_concentration=50.0,
add_key_signatures=True)
except chord_inference.ChordInferenceError:
Metrics.counter('extract_examples',
'chord_inference_failed').inc()
continue
# Infer melody regardless of relative/absolute timing.
try:
melody_instrument = melody_inference.infer_melody_for_sequence(
performance_sequence,
melody_interval_scale=2.0,
rest_prob=0.1,
instantaneous_non_max_pitch_prob=1e-15,
instantaneous_non_empty_rest_prob=0.0,
instantaneous_missing_pitch_prob=1e-15)
except melody_inference.MelodyInferenceError:
Metrics.counter('extract_examples',
'melody_inference_failed').inc()
continue
if not self._absolute_timing:
# Now rectify detected beats to occur at fixed tempo.
# TODO(iansimon): also include the alignment
score_sequence, unused_alignment = sequences_lib.rectify_beats(
performance_sequence, beats_per_minute=SCORE_BPM)
else:
# Score uses same timing as performance.
score_sequence = copy.deepcopy(performance_sequence)
# Remove melody notes from performance.
performance_notes = []
for note in performance_sequence.notes:
if note.instrument != melody_instrument:
performance_notes.append(note)
del performance_sequence.notes[:]
performance_sequence.notes.extend(performance_notes)
# Remove non-melody notes from score.
score_notes = []
for note in score_sequence.notes:
if note.instrument == melody_instrument:
score_notes.append(note)
del score_sequence.notes[:]
score_sequence.notes.extend(score_notes)
# Remove key signatures and beat/chord annotations from performance.
del performance_sequence.key_signatures[:]
del performance_sequence.text_annotations[:]
Metrics.counter('extract_examples', 'extracted_score').inc()
for augment_fn in self._augment_fns:
# Augment and encode the performance.
try:
augmented_performance_sequence = augment_fn(
performance_sequence)
except DataAugmentationError:
Metrics.counter('extract_examples',
'augment_performance_failed').inc()
continue
example_dict = {
'targets':
self._encode_performance_fn(augmented_performance_sequence)
}
if not example_dict['targets']:
Metrics.counter('extract_examples',
'skipped_empty_targets').inc()
continue
if (self._random_crop_length and len(example_dict['targets']) >
self._random_crop_length):
# Take a random crop of the encoded performance.
max_offset = len(
example_dict['targets']) - self._random_crop_length
offset = random.randrange(max_offset + 1)
example_dict['targets'] = example_dict['targets'][
offset:offset + self._random_crop_length]
if self._encode_score_fns:
# Augment the extracted score.
try:
augmented_score_sequence = augment_fn(score_sequence)
except DataAugmentationError:
Metrics.counter('extract_examples',
'augment_score_failed').inc()
continue
# Apply all score encoding functions.
skip = False
for name, encode_score_fn in self._encode_score_fns.items(
):
example_dict[name] = encode_score_fn(
augmented_score_sequence)
if not example_dict[name]:
Metrics.counter('extract_examples',
'skipped_empty_%s' % name).inc()
skip = True
break
if skip:
continue
Metrics.counter('extract_examples', 'encoded_example').inc()
Metrics.distribution(
'extract_examples',
'performance_length_in_seconds').update(
int(augmented_performance_sequence.total_time))
yield generator_utils.to_example(example_dict)