STT/lm_optimizer.py

88 lines
2.5 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function
import sys
import optuna
import tensorflow.compat.v1 as tfv1
from coqui_stt_ctcdecoder import Scorer
from coqui_stt_training.evaluate import evaluate
from coqui_stt_training.train import create_model, early_training_checks
from coqui_stt_training.util.config import (
Config,
initialize_globals_from_cli,
log_error,
)
from coqui_stt_training.util.evaluate_tools import wer_cer_batch
def character_based():
is_character_based = False
scorer = Scorer(
Config.lm_alpha, Config.lm_beta, Config.scorer_path, Config.alphabet
)
is_character_based = scorer.is_utf8_mode()
return is_character_based
def objective(trial):
Config.lm_alpha = trial.suggest_uniform("lm_alpha", 0, Config.lm_alpha_max)
Config.lm_beta = trial.suggest_uniform("lm_beta", 0, Config.lm_beta_max)
is_character_based = trial.study.user_attrs["is_character_based"]
samples = []
for step, test_file in enumerate(Config.test_files):
tfv1.reset_default_graph()
current_samples = evaluate([test_file], create_model)
samples += current_samples
# Report intermediate objective value.
wer, cer = wer_cer_batch(current_samples)
trial.report(cer if is_character_based else wer, step)
# Handle pruning based on the intermediate value.
if trial.should_prune():
raise optuna.exceptions.TrialPruned()
wer, cer = wer_cer_batch(samples)
return cer if is_character_based else wer
def main():
initialize_globals_from_cli()
early_training_checks()
if not Config.scorer_path:
log_error(
"Missing --scorer_path: can't optimize scorer alpha and beta "
"parameters without a scorer!"
)
sys.exit(1)
if not Config.test_files:
log_error(
"You need to specify what files to use for evaluation via "
"the --test_files flag."
)
sys.exit(1)
is_character_based = character_based()
study = optuna.create_study()
study.set_user_attr("is_character_based", is_character_based)
study.optimize(objective, n_jobs=1, n_trials=Config.n_trials)
print(
"Best params: lm_alpha={} and lm_beta={} with WER={}".format(
study.best_params["lm_alpha"],
study.best_params["lm_beta"],
study.best_value,
)
)
if __name__ == "__main__":
main()