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58 lines
2.3 KiB
58 lines
2.3 KiB
# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Contain the speech perturbation augmentation model."""
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from deepspeech.frontend.augmentor.base import AugmentorBase
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class SpeedPerturbAugmentor(AugmentorBase):
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"""Augmentation model for adding speed perturbation.
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See reference paper here:
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http://www.danielpovey.com/files/2015_interspeech_augmentation.pdf
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:param rng: Random generator object.
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:type rng: random.Random
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:param min_speed_rate: Lower bound of new speed rate to sample and should
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not be smaller than 0.9.
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:type min_speed_rate: float
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:param max_speed_rate: Upper bound of new speed rate to sample and should
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not be larger than 1.1.
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:type max_speed_rate: float
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"""
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def __init__(self, rng, min_speed_rate, max_speed_rate):
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if min_speed_rate < 0.9:
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raise ValueError(
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"Sampling speed below 0.9 can cause unnatural effects")
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if max_speed_rate > 1.1:
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raise ValueError(
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"Sampling speed above 1.1 can cause unnatural effects")
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self._min_speed_rate = min_speed_rate
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self._max_speed_rate = max_speed_rate
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self._rng = rng
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def transform_audio(self, audio_segment):
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"""Sample a new speed rate from the given range and
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changes the speed of the given audio clip.
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Note that this is an in-place transformation.
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:param audio_segment: Audio segment to add effects to.
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:type audio_segment: AudioSegment|SpeechSegment
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"""
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sampled_speed = self._rng.uniform(self._min_speed_rate,
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self._max_speed_rate)
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audio_segment.change_speed(sampled_speed)
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