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19 lines
381 B
Python
19 lines
381 B
Python
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import numpy as np
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import math
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scale = 255.0/32768.0
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scale_1 = 32768.0/255.0
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def ulaw2lin(u):
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u = u - 128
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s = np.sign(u)
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u = np.abs(u)
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return s*scale_1*(np.exp(u/128.*math.log(256))-1)
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def lin2ulaw(x):
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s = np.sign(x)
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x = np.abs(x)
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u = (s*(128*np.log(1+scale*x)/math.log(256)))
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u = np.clip(128 + np.round(u), 0, 255)
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return u.astype('int16')
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