youtube-music-transcribe / inferencemodel.py
juancopi81's picture
Change model to ismir
bde4867
import functools
import numpy as np
import tensorflow.compat.v2 as tf
import functools
import gin
import jax
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
class InferenceModel(object):
"""Wrapper of T5X model for music transcription."""
def __init__(self, checkpoint_path, model_type='ismir2021'):
# 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 = ['/home/user/app/mt3/gin/model.gin',
'/home/user/app/mt3/gin/mt3.gin']
self.batch_size = 8
self.outputs_length = 1024
self.sequence_length = {'inputs': self.inputs_length,
'targets': self.outputs_length}
self.partitioner = t5x.partitioning.PjitPartitioner(
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',
'VOCAB_CONFIG=@vocabularies.VocabularyConfig()',
'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