======= morgana

Morgana (GitHub <https://github.com/ZackHodari/morgana>) (docs <https://zackhodari.github.io/morgana/>) is a toolkit for defining and training Text-to-Speech voices in PyTorch.

Installation

To install as a package, from source:

.. code-block:: bash

pip install git+https://github.com/ZackHodari/morgana

To clone as a git repo, allowing for local modifications to the source code:

.. code-block:: bash

git clone https://github.com/ZackHodari/morgana
cd morgana
python setup.py develop

Design

The support code necessary for creating Text-to-Speech (TTS) voices is not over complicated, but does require time to piece together. Existing packages like Merlin <https://github.com/CSTR-Edinburgh/merlin> provide an easy to use toolkit for training voices, but Merlin obfuscates too many details, and makes modifications hard without changing the source code. Similar to nnmnkwii <https://github.com/r9y9/nnmnkwii>, Morgana aims to provide flexibility in defining your own models. However, Morgana attempts to automate as much of the support code as possible, while still allowing for customisation where necessary.

Defining a model

For most use-cases, the classes provided in base_models.py <https://github.com/ZackHodari/morgana/blob/master/morgana/base_models.py>_ is all that needs to be extended. For example, create a subclass of :class:morgana.base_models.BaseSPSS and implement train_data_sources, predict, and loss.

• __init__: Create the layers for your model.
• train_data_sources: Define a dictionary containing instances that are subclasses of morgana.data._DataSource.
• predict: Define any arbitrary computation in PyTorch.
• loss: Define the targets (from features) and predictions (output of predict) used to calculate the loss. A sequence length feature can also be specified (for each target-prediction pair).

.. code-block::

import torch.nn as nn
from morgana import data
from morgana import utils
from morgana.base_models import BaseSPSS
from morgana.experiment_builder import ExperimentBuilder

class F0Model(BaseSPSS):
    def __init__(self, normalisers=None):
        super(F0Model, self).__init__(normalisers=normalisers)

        self.layers = nn.Sequential(
            nn.Linear(600, 512),
            nn.Sigmoid(),
            nn.Linear(512, 128),
            nn.Sigmoid(),
            nn.Linear(128, 32),
            nn.Sigmoid(),
            nn.Linear(32, 1)
        )

    @classmethod
    def train_data_sources(cls):
        return {
            'n_frames': data.TextSource('n_frames'),
            'dur': data.TextSource('dur', normalisation='mvn'),
            'lab': data.NumpyBinarySource('lab', normalisation='minmax'),
            'lf0': data.NumpyBinarySource('lf0', normalisation='mvn'),
        }

    def predict(self, features):
        norm_lab_at_frame_rate = utils.upsample_to_repetitions(features['normalised_lab'], features['dur'])
        pred_norm_lf0 = self.layers(norm_lab_at_frame_rate, seq_len=features['n_frames'])
        pred_lf0 = self.normalisers['lf0'].denormalise(pred_norm_lf0)

        return {'pred_norm_lf0': pred_norm_lf0,
                'pred_lf0': pred_lf0}

    def loss(self, features, output_features):
        target_norm_lf0 = features['normalised_lf0']
        pred_norm_lf0 = output_features['pred_norm_lf0']
        seq_len = features['n_frames']

        return self._loss(target_norm_lf0, pred_norm_lf0, seq_len)

Running an experiment

Most models can be run using classes provided in experiment_builder.py <https://github.com/ZackHodari/morgana/blob/master/morgana/experiment_builder.py>_. If different training procedures are needed, then a new :class:morgana.experiment_builder.ExperimentBuilder subclass may be required. An ExperimentBuilder contains the following important methods,

• add_args: Defines the command lines arguments supported for experiments of this type.
• __init__:
  • Saves command line arguments as instance attributes.
  • Calls resolve_setting_conflicts.
  • Loads normalisers and data specified in train_data_sources.
  • Creates the model. Loads from a checkpoint. Creates an exponential moving average (EMA) instance of the model.
  • Sets up Python logging, saves stdout and stderr to files. Saves tqdm output to a separate log file.
• resolve_setting_conflicts: Check (and modify) any command line arguments that are incorrect (or inconsistent).
• train_epoch: Epoch loop that iterates through ExperimentBuilder.train_iter.
• run_train: Training loop that calls train_epoch until ExperimentBuilder.epoch reaches ExperimentBuilder.end_epoch.
• valid_epoch: Epoch loop that iterates through ExperimentBuilder.valid_iter.
• run_valid: Runs validation of the current model (or EMA model), and reports the validation loss.
• test_epoch: Epoch loop that iterates through ExperimentBuilder.test_iter.
• run_test: Runs generation of the current model (or EMA model), no loss will be reported (no labels are given).
• run_experiment: Runs run_train, run_valid, and run_test according to the command line arguments.

At the bottom of the file containing F0Model place the following,

.. code-block::

def main():
    args = ExperimentBuilder.get_experiment_args()
    experiment = ExperimentBuilder(F0Model, **args)
    experiment.run_experiment()

if __name__ == "__main__":
    main()

The model can then be trained using the following command (see tts_data_tools <https://github.com/ZackHodari/tts_data_tools>_ for guidance on pre-processing of data),

.. code-block:: bash

python acoustic_model.py \
    --experiment_name DNN_voice \
    --data_root ~/data/Blizzard2017 \
    --train_dir train \
    --train_id_list train_file_id_list.scp \
    --valid_dir valid \
    --valid_id_list valid_file_id_list.scp