Read the data of a single channel from a stereo wave file in Python
python, scipy, wave
Solution
`scipy.io.wavfile.read` returns the tuple `(rate, data)`. If the file is stereo, `data` is a numpy array with shape `(nsamples, 2)`. To get a specific channel, use a slice of `data`. For example,
rate, data = wavfile.read(path)
# data0 is the data from channel 0.
data0 = data[:, 0]
Problem
I have to read the data from just one channel in a stereo wave file in Python. For this I tried it with scipy.io: ``` import scipy.io.wavfile as wf import numpy def read(path): data = wf.read(path) for frame in data[1]: data = numpy.append(data, frame[0]) return data ``` But this code is very slow, especially if I have to work with longer files. So does anybody know a faster way to do this? I thought about the standard wave module by using wave.readframes(), but how are the frames stored there?