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108 lines
3.6 KiB
108 lines
3.6 KiB
# Copyright (c) 2022 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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from typing import Union
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import numpy as np
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__all__ = ["pcm16to32", "depth_convert"]
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def pcm16to32(audio: np.ndarray) -> np.ndarray:
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"""pcm int16 to float32
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Args:
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audio (np.ndarray): Waveform with dtype of int16.
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Returns:
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np.ndarray: Waveform with dtype of float32.
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"""
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if audio.dtype == np.int16:
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audio = audio.astype("float32")
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bits = np.iinfo(np.int16).bits
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audio = audio / (2**(bits - 1))
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return audio
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def _safe_cast(y: np.ndarray, dtype: Union[type, str]) -> np.ndarray:
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"""Data type casting in a safe way, i.e., prevent overflow or underflow.
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Args:
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y (np.ndarray): Input waveform array in 1D or 2D.
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dtype (Union[type, str]): Data type of waveform.
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Returns:
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np.ndarray: `y` after safe casting.
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"""
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if 'float' in str(y.dtype):
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return np.clip(y, np.finfo(dtype).min,
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np.finfo(dtype).max).astype(dtype)
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else:
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return np.clip(y, np.iinfo(dtype).min,
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np.iinfo(dtype).max).astype(dtype)
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def depth_convert(y: np.ndarray, dtype: Union[type, str]) -> np.ndarray:
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"""Convert audio array to target dtype safely.
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This function convert audio waveform to a target dtype, with addition steps of
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preventing overflow/underflow and preserving audio range.
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Args:
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y (np.ndarray): Input waveform array in 1D or 2D.
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dtype (Union[type, str]): Data type of waveform.
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Returns:
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np.ndarray: `y` after safe casting.
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"""
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SUPPORT_DTYPE = ['int16', 'int8', 'float32', 'float64']
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if y.dtype not in SUPPORT_DTYPE:
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raise ParameterError(
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'Unsupported audio dtype, '
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f'y.dtype is {y.dtype}, supported dtypes are {SUPPORT_DTYPE}')
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if dtype not in SUPPORT_DTYPE:
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raise ParameterError(
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'Unsupported audio dtype, '
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f'target dtype is {dtype}, supported dtypes are {SUPPORT_DTYPE}')
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if dtype == y.dtype:
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return y
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if dtype == 'float64' and y.dtype == 'float32':
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return _safe_cast(y, dtype)
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if dtype == 'float32' and y.dtype == 'float64':
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return _safe_cast(y, dtype)
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if dtype == 'int16' or dtype == 'int8':
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if y.dtype in ['float64', 'float32']:
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factor = np.iinfo(dtype).max
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y = np.clip(y * factor, np.iinfo(dtype).min,
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np.iinfo(dtype).max).astype(dtype)
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y = y.astype(dtype)
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else:
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if dtype == 'int16' and y.dtype == 'int8':
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factor = np.iinfo('int16').max / np.iinfo('int8').max - EPS
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y = y.astype('float32') * factor
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y = y.astype('int16')
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else: # dtype == 'int8' and y.dtype=='int16':
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y = y.astype('int32') * np.iinfo('int8').max / \
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np.iinfo('int16').max
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y = y.astype('int8')
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if dtype in ['float32', 'float64']:
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org_dtype = y.dtype
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y = y.astype(dtype) / np.iinfo(org_dtype).max
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return y
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