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pythonwav

How to create multichannel .WAV file in Python?

The .WAV format looks like it should allow more than two channels (nChannels).

But unfortunately scipy.io.wavfile only writes 1 or 2.

I don't really want to manually write my own Python WAV-writer, but I can't find anything out there.

Is there any code out there that does the job?

Solution

  • It turns out the documentation for scipy.io.wavfile is incorrect.

    Looking at the source code, I can clearly see that it accepts an arbitrary number of channels.

    The following code works:

    import numpy as np
from scipy.io import wavfile

fs = 48000
nsamps = fs * 10

A, Csharp, E, G = 440.0, 554.365, 660.0, 783.991

def sine(freqHz):
    τ = 2 * np.pi
    return np.sin( 
        np.linspace(0,  τ * freqHz * nsamps / fs,  nsamps,  endpoint=False)
    )

A7_chord = np.array( [ sine(A), sine(Csharp), sine(E), sine(G) ] ).T

wavfile.write("A7--4channel.wav", fs, A7_chord)