Audio analysis

getfiles.sh

#!/bin/bash

wget -O stereo_2205k_16bit.wav http://download.wavetlan.com/SVV/Media/HTTP/test_stereo_22050Hz_16bit_PCM.wav

wget -O mono_441k_8bit.wav http://download.wavetlan.com/SVV/Media/HTTP/test_mono_44100Hz_8bit_PCM.wav

requirements.txt

scipy

thingy.py

#!/usr/bin/python3

# Get the test files (run the 'getfiles.sh') and
# install scipy: "pip install scipy"
# (or "pip install -r requirements.txt")
# -----
# Based on:
# http://stackoverflow.com/questions/10222812/python-numpy-fft-and-inverse-fft
# http://stackoverflow.com/questions/23377665/python-scipy-fft-wav-files


from scipy.fftpack import rfft, irfft
from scipy.io import wavfile
import numpy

target = 'mono_441k_8bit.wav'
#target = 'stereo_2205k_16bit.wav'

fs, data = wavfile.read(target)

print('Analysing: {}'.format(target))
print("Frame rate: {}/sec".format(fs))
print("Bitrate: {}".format(data.T.dtype.name))

if len(data.T) == 2:
    print("Original data (left channel): ", data.T[0])
    print("Original data (right channel): ", data.T[1])
else:
    print("Original data: {}".format(data.T))

rf = rfft(data.T, axis=0)
print("FFT:")
print(rf)

irf = irfft(rf, axis=0)
irf = numpy.round(irf).astype('int16')  
print("IFFT:")
print(irf)

newname = target.split('.')[0] + '_post.wav'
print("Saving IFFT to {}".format(newname))
wavfile.write(newname, fs, irf)