You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
PaddleSpeech/deepspeech/decoders/utils.py

50 lines
1.6 KiB

# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
__all__ = ["end_detect"]
def end_detect(ended_hyps, i, M=3, D_end=np.log(1 * np.exp(-10))):
"""End detection.
described in Eq. (50) of S. Watanabe et al
"Hybrid CTC/Attention Architecture for End-to-End Speech Recognition"
:param ended_hyps: dict
:param i: int
:param M: int
:param D_end: float
:return: bool
"""
if len(ended_hyps) == 0:
return False
count = 0
best_hyp = sorted(ended_hyps, key=lambda x: x["score"], reverse=True)[0]
for m in range(M):
# get ended_hyps with their length is i - m
hyp_length = i - m
hyps_same_length = [
x for x in ended_hyps if len(x["yseq"]) == hyp_length
]
if len(hyps_same_length) > 0:
best_hyp_same_length = sorted(
hyps_same_length, key=lambda x: x["score"], reverse=True)[0]
if best_hyp_same_length["score"] - best_hyp["score"] < D_end:
count += 1
if count == M:
return True
else:
return False