29 lines
1.1 KiB
Python
29 lines
1.1 KiB
Python
try:
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import librosa
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except ImportError: # pragma: no-cover
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raise ImportError('You want to use `librosa` plugins which are not installed yet,' # pragma: no-cover
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' install it with `pip install librosa`.')
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import numpy as np
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class Speed(object):
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def __init__(self, max_amount=0.3, speed_min=1, speed_max=1):
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self.speed_max = speed_max
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self.speed_min = speed_min
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self.max_amount = max_amount
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def __call__(self, x):
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assert all([self.speed_min, self.speed_max, self.max_amount])
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start = int(np.random.randint(low=0, high=x.shape[-1], size=1))
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width = np.random.uniform(low=0, high=self.max_amount, size=1) * x.shape[-1]
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end = int(width + start)
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end = min(end, x.shape[-1])
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try:
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speed_factor = float(np.random.uniform(low=self.speed_min, high=self.speed_max, size=1))
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aug_data = librosa.effects.time_stretch(x[start:end], speed_factor)
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return np.concatenate((x[:start], aug_data, x[end:]), axis=0)[:x.shape[-1]]
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except ValueError:
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return x
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