app.py

import os
os.system("pip install gradio")

import gradio as gr
from pathlib import Path
os.system("pip install gsutil")


os.system("git clone --branch=main https://github.com/google-research/t5x")
os.system("mv t5x t5x_tmp; mv t5x_tmp/* .; rm -r t5x_tmp")
os.system("sed -i 's:jax\[tpu\]:jax:' setup.py")
os.system("python3 -m pip install -e .")
os.system("python3 -m pip install --upgrade pip")


# 安装 mt3
os.system("git clone --branch=main https://github.com/magenta/mt3")
os.system("mv mt3 mt3_tmp; mv mt3_tmp/* .; rm -r mt3_tmp")
os.system("python3 -m pip install -e .")
os.system("pip install tensorflow_cpu")
# 复制检查点
os.system("gsutil -q -m cp -r gs://mt3/checkpoints .")

# 复制 soundfont 文件（原始文件来自 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 导入和定义


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(audio, sample_rate):
  return note_seq.audio_io.wav_data_to_samples_librosa(
    audio, sample_rate=sample_rate)



class InferenceModel(object):
  """音乐转录的 T5X 模型包装器。"""

  def __init__(self, checkpoint_path, model_type='mt3'):

    # 模型常量。
    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=None, num_partitions=1)

    # 构建编解码器和词汇表。
    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),
    }

    # 创建 T5X 模型。
    self._parse_gin(gin_files)
    self.model = self._load_model()

    # 从检查点中恢复。
    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):
    """解析用于训练模型的 gin 文件。"""
    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):
    """在解析训练 gin 配置后加载 T5X `Model`。"""
    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):
    """从检查点中恢复训练状态，重置 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):
    """生成一个分区的预测函数用于解码。"""
    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):
    """从预处理的数据集批次中预测 tokens。"""
    prediction, _ = self._predict_fn(
self._train_state.params, batch, jax.random.PRNGKey(seed))
    return self.vocabulary.decode_tf(prediction).numpy()

  def __call__(self, audio):
    """从音频样本推断出音符序列。
    
    参数：
      audio：16kHz 的单个音频样本的 1 维 numpy 数组。
    返回：
      转录音频的音符序列。
    """
    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):
    """从输入音频创建一个包含频谱图的 TF Dataset。"""
    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):
    """从音频计算频谱图帧。"""
    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']),
        # 在训练期间进行缓存。
        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]
    # 向下取整到最接近的符号化时间步。
    start_time -= start_time % (1 / self.codec.steps_per_second)
    return {
        'est_tokens': tokens,
        'start_time': start_time,
        # 内部 MT3 代码期望原始输入，这里不使用。
        '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






inference_model = InferenceModel('/home/user/app/checkpoints/mt3/', 'mt3')


def inference(audio):
  with open(audio, 'rb') as fd:
      contents = fd.read()
  audio = upload_audio(contents,sample_rate=16000)
  
  est_ns = inference_model(audio)
  
  note_seq.sequence_proto_to_midi_file(est_ns, './transcribed.mid')
 
  return './transcribed.mid'
  
title = "MT3"
description = "MT3：多任务多音轨音乐转录的 Gradio 演示。要使用它，只需上传音频文件，或点击示例以加载它们。更多信息请参阅下面的链接。"

article = "<p style='text-align: center'>出错了？试试把文件转换为MP3后再上传吧~</p><p style='text-align: center'><a href='https://arxiv.org/abs/2111.03017' target='_blank'>MT3: 多任务多音轨音乐转录</a> | <a href='https://github.com/magenta/mt3' target='_blank'>Github 仓库</a></p>"

examples=[['canon.flac'], ['download.wav']]

gr.Interface(
    inference, 
    gr.inputs.Audio(type="filepath", label="输入"), 
    [gr.outputs.File(label="输出")],
    title=title,
    description=description,
    article=article,
    examples=examples, 
    allow_flagging=False,
    allow_screenshot=False,
    enable_queue=True
    ).launch()