コード例 #1
0
    def testInferChordsForSequence(self):
        sequence = music_pb2.NoteSequence()
        testing_lib.add_track_to_sequence(
            sequence,
            0,
            [
                (60, 100, 0.0, 1.0),
                (64, 100, 0.0, 1.0),
                (67, 100, 0.0, 1.0),  # C
                (62, 100, 1.0, 2.0),
                (65, 100, 1.0, 2.0),
                (69, 100, 1.0, 2.0),  # Dm
                (60, 100, 2.0, 3.0),
                (65, 100, 2.0, 3.0),
                (69, 100, 2.0, 3.0),  # F
                (59, 100, 3.0, 4.0),
                (62, 100, 3.0, 4.0),
                (67, 100, 3.0, 4.0)
            ])  # G
        quantized_sequence = sequences_lib.quantize_note_sequence(
            sequence, steps_per_quarter=4)
        chord_inference.infer_chords_for_sequence(quantized_sequence,
                                                  chords_per_bar=2)

        expected_chords = [('C', 0.0), ('Dm', 1.0), ('F', 2.0), ('G', 3.0)]
        chords = [(ta.text, ta.time)
                  for ta in quantized_sequence.text_annotations]

        self.assertEqual(expected_chords, chords)
コード例 #2
0
    def testInferChordsForSequenceWithBeats(self):
        sequence = music_pb2.NoteSequence()
        testing_lib.add_track_to_sequence(
            sequence,
            0,
            [
                (60, 100, 0.0, 1.1),
                (64, 100, 0.0, 1.1),
                (67, 100, 0.0, 1.1),  # C
                (62, 100, 1.1, 1.9),
                (65, 100, 1.1, 1.9),
                (69, 100, 1.1, 1.9),  # Dm
                (60, 100, 1.9, 3.0),
                (65, 100, 1.9, 3.0),
                (69, 100, 1.9, 3.0),  # F
                (59, 100, 3.0, 4.5),
                (62, 100, 3.0, 4.5),
                (67, 100, 3.0, 4.5)
            ])  # G
        testing_lib.add_beats_to_sequence(sequence, [0.0, 1.1, 1.9, 1.9, 3.0])
        chord_inference.infer_chords_for_sequence(sequence)

        expected_chords = [('C', 0.0), ('Dm', 1.1), ('F', 1.9), ('G', 3.0)]
        chords = [(ta.text, ta.time) for ta in sequence.text_annotations
                  if ta.annotation_type == CHORD_SYMBOL]

        self.assertEqual(expected_chords, chords)
コード例 #3
0
  def testInferChordsForSequenceWithBeats(self):
    sequence = music_pb2.NoteSequence()
    testing_lib.add_track_to_sequence(
        sequence, 0,
        [(60, 100, 0.0, 1.1), (64, 100, 0.0, 1.1), (67, 100, 0.0, 1.1),   # C
         (62, 100, 1.1, 1.9), (65, 100, 1.1, 1.9), (69, 100, 1.1, 1.9),   # Dm
         (60, 100, 1.9, 3.0), (65, 100, 1.9, 3.0), (69, 100, 1.9, 3.0),   # F
         (59, 100, 3.0, 4.5), (62, 100, 3.0, 4.5), (67, 100, 3.0, 4.5)])  # G
    testing_lib.add_beats_to_sequence(sequence, [0.0, 1.1, 1.9, 1.9, 3.0])
    chord_inference.infer_chords_for_sequence(sequence)

    expected_chords = [('C', 0.0), ('Dm', 1.1), ('F', 1.9), ('G', 3.0)]
    chords = [(ta.text, ta.time) for ta in sequence.text_annotations
              if ta.annotation_type == CHORD_SYMBOL]

    self.assertEqual(expected_chords, chords)
コード例 #4
0
  def testInferChordsForSequence(self):
    sequence = music_pb2.NoteSequence()
    testing_lib.add_track_to_sequence(
        sequence, 0,
        [(60, 100, 0.0, 1.0), (64, 100, 0.0, 1.0), (67, 100, 0.0, 1.0),   # C
         (62, 100, 1.0, 2.0), (65, 100, 1.0, 2.0), (69, 100, 1.0, 2.0),   # Dm
         (60, 100, 2.0, 3.0), (65, 100, 2.0, 3.0), (69, 100, 2.0, 3.0),   # F
         (59, 100, 3.0, 4.0), (62, 100, 3.0, 4.0), (67, 100, 3.0, 4.0)])  # G
    quantized_sequence = sequences_lib.quantize_note_sequence(
        sequence, steps_per_quarter=4)
    chord_inference.infer_chords_for_sequence(
        quantized_sequence, chords_per_bar=2)

    expected_chords = [('C', 0.0), ('Dm', 1.0), ('F', 2.0), ('G', 3.0)]
    chords = [(ta.text, ta.time) for ta in quantized_sequence.text_annotations]

    self.assertEqual(expected_chords, chords)
コード例 #5
0
    def testInferChordsForSequenceAddKeySignatures(self):
        sequence = music_pb2.NoteSequence()
        testing_lib.add_track_to_sequence(
            sequence,
            0,
            [
                (60, 100, 0.0, 1.0),
                (64, 100, 0.0, 1.0),
                (67, 100, 0.0, 1.0),  # C
                (62, 100, 1.0, 2.0),
                (65, 100, 1.0, 2.0),
                (69, 100, 1.0, 2.0),  # Dm
                (60, 100, 2.0, 3.0),
                (65, 100, 2.0, 3.0),
                (69, 100, 2.0, 3.0),  # F
                (59, 100, 3.0, 4.0),
                (62, 100, 3.0, 4.0),
                (67, 100, 3.0, 4.0),  # G
                (66, 100, 4.0, 5.0),
                (70, 100, 4.0, 5.0),
                (73, 100, 4.0, 5.0),  # F#
                (68, 100, 5.0, 6.0),
                (71, 100, 5.0, 6.0),
                (75, 100, 5.0, 6.0),  # G#m
                (66, 100, 6.0, 7.0),
                (71, 100, 6.0, 7.0),
                (75, 100, 6.0, 7.0),  # B
                (65, 100, 7.0, 8.0),
                (68, 100, 7.0, 8.0),
                (73, 100, 7.0, 8.0)
            ])  # C#
        quantized_sequence = sequences_lib.quantize_note_sequence(
            sequence, steps_per_quarter=4)
        chord_inference.infer_chords_for_sequence(quantized_sequence,
                                                  chords_per_bar=2,
                                                  add_key_signatures=True)

        expected_key_signatures = [(0, 0.0), (6, 4.0)]
        key_signatures = [(ks.key, ks.time)
                          for ks in quantized_sequence.key_signatures]
        self.assertEqual(expected_key_signatures, key_signatures)
コード例 #6
0
  def testInferChordsForSequenceAddKeySignatures(self):
    sequence = music_pb2.NoteSequence()
    testing_lib.add_track_to_sequence(
        sequence, 0,
        [(60, 100, 0.0, 1.0), (64, 100, 0.0, 1.0), (67, 100, 0.0, 1.0),   # C
         (62, 100, 1.0, 2.0), (65, 100, 1.0, 2.0), (69, 100, 1.0, 2.0),   # Dm
         (60, 100, 2.0, 3.0), (65, 100, 2.0, 3.0), (69, 100, 2.0, 3.0),   # F
         (59, 100, 3.0, 4.0), (62, 100, 3.0, 4.0), (67, 100, 3.0, 4.0),   # G
         (66, 100, 4.0, 5.0), (70, 100, 4.0, 5.0), (73, 100, 4.0, 5.0),   # F#
         (68, 100, 5.0, 6.0), (71, 100, 5.0, 6.0), (75, 100, 5.0, 6.0),   # G#m
         (66, 100, 6.0, 7.0), (71, 100, 6.0, 7.0), (75, 100, 6.0, 7.0),   # B
         (65, 100, 7.0, 8.0), (68, 100, 7.0, 8.0), (73, 100, 7.0, 8.0)])  # C#
    quantized_sequence = sequences_lib.quantize_note_sequence(
        sequence, steps_per_quarter=4)
    chord_inference.infer_chords_for_sequence(
        quantized_sequence, chords_per_bar=2, add_key_signatures=True)

    expected_key_signatures = [(0, 0.0), (6, 4.0)]
    key_signatures = [(ks.key, ks.time)
                      for ks in quantized_sequence.key_signatures]
    self.assertEqual(expected_key_signatures, key_signatures)
コード例 #7
0
  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)
    random.seed(int(m.hexdigest(), 16))

    # Deserialize NoteSequence proto.
    ns = music_pb2.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 ==
                  music_pb2.NoteSequence.TextAnnotation.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._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)
コード例 #8
0
ファイル: datagen_beam.py プロジェクト: adarob/magenta
  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)
    random.seed(int(m.hexdigest(), 16))

    # Deserialize NoteSequence proto.
    ns = music_pb2.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 ==
                  music_pb2.NoteSequence.TextAnnotation.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._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)
コード例 #9
0
    def process_midi(self, f):
        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

        self._min_hop_size_seconds = 0.0
        self._max_hop_size_seconds = 0.0
        self._num_replications = 1
        self._encode_performance_fn = self.performance_encoder(
        ).encode_note_sequence
        self._encode_score_fns = dict(
            (name, encoder.encode_note_sequence)
            for name, encoder in self.score_encoders())

        augment_params = itertools.product(self.stretch_factors,
                                           self.transpose_amounts)
        augment_fns = [
            functools.partial(augment_note_sequence,
                              stretch_factor=s,
                              transpose_amount=t) for s, t in augment_params
        ]

        self._augment_fns = augment_fns
        self._absolute_timing = self.absolute_timing
        self._random_crop_length = self.random_crop_length_in_datagen
        if self._random_crop_length is not None:
            self._augment_fns = self._augment_fns

        rets = []
        ns = magenta.music.midi_file_to_sequence_proto(f)
        # 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):
            print("sequence_too_short")
            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 ==
                            music_pb2.NoteSequence.TextAnnotation.BEAT)
                        and ta.time <= performance_sequence.total_time
                    ]
                    if len(beats) < 2:
                        print('not_enough_beats')
                        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:
                        print("chord_inference_failed")
                        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:
                    print('melody_inference_failed')
                    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[:]

            for augment_fn in self._augment_fns:
                # Augment and encode the performance.
                try:
                    augmented_performance_sequence = augment_fn(
                        performance_sequence)
                except DataAugmentationError as e:
                    print("augment_performance_failed", e)
                    continue
                example_dict = {
                    'targets':
                    self._encode_performance_fn(augmented_performance_sequence)
                }
                if not example_dict['targets']:
                    print('skipped_empty_targets')
                    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:
                        print('augment_score_failed')
                        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]:
                            print('skipped_empty_%s' % name)
                            skip = True
                            break
                    if skip:
                        continue

                rets.append(example_dict)
        return rets