23 lines
809 B
Python
23 lines
809 B
Python
import librosa
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import numpy as np
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class Speed(object):
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def __init__(self, max_ratio=0.3, speed_factor=1):
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self.speed_factor = speed_factor
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self.max_ratio = max_ratio
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def __call__(self, x):
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if not all([self.speed_factor, self.max_ratio]):
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return x
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start = int(np.random.randint(0, x.shape[-1],1))
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end = int((np.random.uniform(0, self.max_ratio, 1) * x.shape[-1]) + 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(min(self.speed_factor, 1), max(self.speed_factor, 1), 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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