FFT for Spectrograms in Python

Question

How would I go about using Python to read the frequency peaks from a WAV PCM file and then be able to generate an image of it, for spectogram analysis?

I'm trying to make a program that allows you to read any audio file, converting it to WAV PCM, and then finding the peaks and frequency cutoffs.

Answer 1

Python's wave library will let you import the audio. After that, you can use numpy to take an FFT of the audio.

Then, matplotlib makes very nice charts and graphs - absolutely comparable to MATLAB.

It's old as dirt, but this article would probably get you started on almost exactly the problem you're describing (article in Python of course).

Answer 2

Loading WAV files is easy using audiolab:

from audiolab import wavread signal, fs, enc = wavread('test.wav') 

or for reading any general audio format and converting to WAV:

from audiolab import Sndfile sound_file = Sndfile('test.w64', 'r') signal = wave_file.read_frames(wave_file.nframes) 

The spectrogram is built into PyLab:

from pylab import * specgram(signal) 

Specifically, it's part of matplotlib. Here's a better example.