PyAudio, how to determine the frequency and amplitude during recording?

Question

I used the PyAudio default recording example and added numpy and scipy. However, I can use scipy.io.wavefile.read('FILE.wav') after writing the file, and it also gives me this random tuple, for example: (44100, array([[ 0, 0], [-2, 0], [ 0, -2], ..., [-2, -2], [ 1, 3], [ 2, -1]], dtype=int16)) . What does this array give, and do you know how else you can get the frequency / amplitude of each frame of the wav file, preferably during recording?

Answer 1

An array is not random data, it is the wave data of your stereo sound, and 44100 is the sampling frequency. use the following code to build the left channel wave:

 import scipy.io.wavfile as wavfile import numpy as np import pylab as pl rate, data = wavfile.read('FILE.wav') t = np.arange(len(data[:,0]))*1.0/rate pl.plot(t, data[:,0]) pl.show() 

To get the frequency and amplitude of the wave, do FFT. Following the code graph, the power of each frequency bin:

 p = 20*np.log10(np.abs(np.fft.rfft(data[:2048, 0]))) f = np.linspace(0, rate/2.0, len(p)) pl.plot(f, p) pl.xlabel("Frequency(Hz)") pl.ylabel("Power(dB)") pl.show()