Read and write audio wav files with scipy

TODO



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%matplotlib inline

import numpy as np
import matplotlib
matplotlib.rcParams['figure.figsize'] = (12, 9)

# Import Jupyter's sound player widget
# See: https://ipython.org/ipython-doc/dev/api/generated/IPython.display.html#IPython.display.Audio

from IPython.display import Audio

Official documentation: https://docs.scipy.org/doc/scipy/reference/io.html#module-scipy.io.wavfile

Notes

This function cannot read wav files with 24-bit data.

Common data types:

WAV format	Min	Max	NumPy dtype
32-bit floating-point	-1.0	+1.0	float32
32-bit PCM	-2147483648	+2147483647	int32
16-bit PCM	-32768	+32767	int16
8-bit PCM	0	255	uint8

Note that 8-bit PCM is unsigned.

Write wav file



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from scipy.io import wavfile



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sample_rate = 44100 # in samples/sec

t = np.linspace(0, 5, sample_rate*5)
data = np.sin(2*np.pi*220*t) + np.sin(2*np.pi*224*t)
data /= 2.          # to keep data between -1 and 1



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data.min(), data.max()



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wavfile.write("foo.wav", sample_rate, data)



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Audio(data, rate=sample_rate)



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Audio("foo.wav")

Read wav file



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sample_rate, data = wavfile.read("foo.wav")



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sample_rate, data.shape, data.min(), data.max()



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Audio(data, rate=sample_rate)



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plt.plot(data[0:20000]);

Another example



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#!wget -O sound.wav https://github.com/karoldvl/ESC-50/raw/master/audio/1-100038-A-14.wav
!wget -O sound.wav https://github.com/jdhp-misc/sample-sounds/raw/master/piano_notes/386725__luckylux__sol.wav



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sample_rate, data = wavfile.read("sound.wav")



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data.shape



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Audio(data[:,0], rate=sample_rate)



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plt.plot(data[:,0]);



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!rm sound.wav