Update app.py

app.py

@@ -20,6 +20,244 @@ os.system("gsutil -q -m cp -r gs://mt3/checkpoints .")
 # copy soundfont (originally from https://sites.google.com/site/soundfonts4u)
 os.system("gsutil -q -m cp gs://magentadata/soundfonts/SGM-v2.01-Sal-Guit-Bass-V1.3.sf2 .")
 
+#@title Imports and Definitions
+
+import functools
+import os
+
+import numpy as np
+import tensorflow.compat.v2 as tf
+
+import functools
+import gin
+import jax
+import librosa
+import note_seq
+import seqio
+import t5
+import t5x
+
+from mt3 import metrics_utils
+from mt3 import models
+from mt3 import network
+from mt3 import note_sequences
+from mt3 import preprocessors
+from mt3 import spectrograms
+from mt3 import vocabularies
+
+
+import nest_asyncio
+nest_asyncio.apply()
+
+SAMPLE_RATE = 16000
+SF2_PATH = 'SGM-v2.01-Sal-Guit-Bass-V1.3.sf2'
+
+def upload_audio(sample_rate):
+  data = list(files.upload().values())
+  if len(data) > 1:
+    print('Multiple files uploaded; using only one.')
+  return note_seq.audio_io.wav_data_to_samples_librosa(
+    data[0], sample_rate=sample_rate)
+
+
+
+class InferenceModel(object):
+  """Wrapper of T5X model for music transcription."""
+
+  def __init__(self, checkpoint_path, model_type='mt3'):
+
+    # Model Constants.
+    if model_type == 'ismir2021':
+      num_velocity_bins = 127
+      self.encoding_spec = note_sequences.NoteEncodingSpec
+      self.inputs_length = 512
+    elif model_type == 'mt3':
+      num_velocity_bins = 1
+      self.encoding_spec = note_sequences.NoteEncodingWithTiesSpec
+      self.inputs_length = 256
+    else:
+      raise ValueError('unknown model_type: %s' % model_type)
+
+    gin_files = ['/content/mt3/gin/model.gin',
+                 f'/content/mt3/gin/{model_type}.gin']
+
+    self.batch_size = 8
+    self.outputs_length = 1024
+    self.sequence_length = {'inputs': self.inputs_length, 
+                            'targets': self.outputs_length}
+
+    self.partitioner = t5x.partitioning.ModelBasedPjitPartitioner(
+        model_parallel_submesh=(1, 1, 1, 1), num_partitions=1)
+
+    # Build Codecs and Vocabularies.
+    self.spectrogram_config = spectrograms.SpectrogramConfig()
+    self.codec = vocabularies.build_codec(
+        vocab_config=vocabularies.VocabularyConfig(
+            num_velocity_bins=num_velocity_bins))
+    self.vocabulary = vocabularies.vocabulary_from_codec(self.codec)
+    self.output_features = {
+        'inputs': seqio.ContinuousFeature(dtype=tf.float32, rank=2),
+        'targets': seqio.Feature(vocabulary=self.vocabulary),
+    }
+
+    # Create a T5X model.
+    self._parse_gin(gin_files)
+    self.model = self._load_model()
+
+    # Restore from checkpoint.
+    self.restore_from_checkpoint(checkpoint_path)
+
+  @property
+  def input_shapes(self):
+    return {
+          'encoder_input_tokens': (self.batch_size, self.inputs_length),
+          'decoder_input_tokens': (self.batch_size, self.outputs_length)
+    }
+
+  def _parse_gin(self, gin_files):
+    """Parse gin files used to train the model."""
+    gin_bindings = [
+        'from __gin__ import dynamic_registration',
+        'from mt3 import vocabularies',
+        '[email protected]()',
+        'vocabularies.VocabularyConfig.num_velocity_bins=%NUM_VELOCITY_BINS'
+    ]
+    with gin.unlock_config():
+      gin.parse_config_files_and_bindings(
+          gin_files, gin_bindings, finalize_config=False)
+
+  def _load_model(self):
+    """Load up a T5X `Model` after parsing training gin config."""
+    model_config = gin.get_configurable(network.T5Config)()
+    module = network.Transformer(config=model_config)
+    return models.ContinuousInputsEncoderDecoderModel(
+        module=module,
+        input_vocabulary=self.output_features['inputs'].vocabulary,
+        output_vocabulary=self.output_features['targets'].vocabulary,
+        optimizer_def=t5x.adafactor.Adafactor(decay_rate=0.8, step_offset=0),
+        input_depth=spectrograms.input_depth(self.spectrogram_config))
+
+
+  def restore_from_checkpoint(self, checkpoint_path):
+    """Restore training state from checkpoint, resets self._predict_fn()."""
+    train_state_initializer = t5x.utils.TrainStateInitializer(
+      optimizer_def=self.model.optimizer_def,
+      init_fn=self.model.get_initial_variables,
+      input_shapes=self.input_shapes,
+      partitioner=self.partitioner)
+
+    restore_checkpoint_cfg = t5x.utils.RestoreCheckpointConfig(
+        path=checkpoint_path, mode='specific', dtype='float32')
+
+    train_state_axes = train_state_initializer.train_state_axes
+    self._predict_fn = self._get_predict_fn(train_state_axes)
+    self._train_state = train_state_initializer.from_checkpoint_or_scratch(
+        [restore_checkpoint_cfg], init_rng=jax.random.PRNGKey(0))
+
+  @functools.lru_cache()
+  def _get_predict_fn(self, train_state_axes):
+    """Generate a partitioned prediction function for decoding."""
+    def partial_predict_fn(params, batch, decode_rng):
+      return self.model.predict_batch_with_aux(
+          params, batch, decoder_params={'decode_rng': None})
+    return self.partitioner.partition(
+        partial_predict_fn,
+        in_axis_resources=(
+            train_state_axes.params,
+            t5x.partitioning.PartitionSpec('data',), None),
+        out_axis_resources=t5x.partitioning.PartitionSpec('data',)
+    )
+
+  def predict_tokens(self, batch, seed=0):
+    """Predict tokens from preprocessed dataset batch."""
+    prediction, _ = self._predict_fn(
+        self._train_state.params, batch, jax.random.PRNGKey(seed))
+    return self.vocabulary.decode_tf(prediction).numpy()
+
+  def __call__(self, audio):
+    """Infer note sequence from audio samples.
+    
+    Args:
+      audio: 1-d numpy array of audio samples (16kHz) for a single example.
+
+    Returns:
+      A note_sequence of the transcribed audio.
+    """
+    ds = self.audio_to_dataset(audio)
+    ds = self.preprocess(ds)
+
+    model_ds = self.model.FEATURE_CONVERTER_CLS(pack=False)(
+        ds, task_feature_lengths=self.sequence_length)
+    model_ds = model_ds.batch(self.batch_size)
+
+    inferences = (tokens for batch in model_ds.as_numpy_iterator()
+                  for tokens in self.predict_tokens(batch))
+
+    predictions = []
+    for example, tokens in zip(ds.as_numpy_iterator(), inferences):
+      predictions.append(self.postprocess(tokens, example))
+
+    result = metrics_utils.event_predictions_to_ns(
+        predictions, codec=self.codec, encoding_spec=self.encoding_spec)
+    return result['est_ns']
+
+  def audio_to_dataset(self, audio):
+    """Create a TF Dataset of spectrograms from input audio."""
+    frames, frame_times = self._audio_to_frames(audio)
+    return tf.data.Dataset.from_tensors({
+        'inputs': frames,
+        'input_times': frame_times,
+    })
+
+  def _audio_to_frames(self, audio):
+    """Compute spectrogram frames from audio."""
+    frame_size = self.spectrogram_config.hop_width
+    padding = [0, frame_size - len(audio) % frame_size]
+    audio = np.pad(audio, padding, mode='constant')
+    frames = spectrograms.split_audio(audio, self.spectrogram_config)
+    num_frames = len(audio) // frame_size
+    times = np.arange(num_frames) / self.spectrogram_config.frames_per_second
+    return frames, times
+
+  def preprocess(self, ds):
+    pp_chain = [
+        functools.partial(
+            t5.data.preprocessors.split_tokens_to_inputs_length,
+            sequence_length=self.sequence_length,
+            output_features=self.output_features,
+            feature_key='inputs',
+            additional_feature_keys=['input_times']),
+        # Cache occurs here during training.
+        preprocessors.add_dummy_targets,
+        functools.partial(
+            preprocessors.compute_spectrograms,
+            spectrogram_config=self.spectrogram_config)
+    ]
+    for pp in pp_chain:
+      ds = pp(ds)
+    return ds
+
+  def postprocess(self, tokens, example):
+    tokens = self._trim_eos(tokens)
+    start_time = example['input_times'][0]
+    # Round down to nearest symbolic token step.
+    start_time -= start_time % (1 / self.codec.steps_per_second)
+    return {
+        'est_tokens': tokens,
+        'start_time': start_time,
+        # Internal MT3 code expects raw inputs, not used here.
+        'raw_inputs': []
+    }
+
+  @staticmethod
+  def _trim_eos(tokens):
+    tokens = np.array(tokens, np.int32)
+    if vocabularies.DECODED_EOS_ID in tokens:
+      tokens = tokens[:np.argmax(tokens == vocabularies.DECODED_EOS_ID)]
+    return tokens
+
+
+
 
 def inference(audio):
   os.system("midi_ddsp_synthesize --midi_path "+audio.name)