Plot spectogram from mp3

Question

I am trying to plot a spectogram straight from an mp3 file in python 2.7.3 (using ubuntu). I can do it from a wav file as follows.

#!/usr/bin/python
from scikits.audiolab import wavread
from pylab import *

signal, fs, enc = wavread('XC124158.wav')
specgram(signal)
show()

What's the cleanest way to do the same thing from an mp3 file instead of a wav? I don't want to convert all the mp3 files to wav if I can avoid it.

Answer 1

Another very simple way of plotting spectrogram of mp3 file.

from pydub import AudioSegment
import matplotlib.pyplot as plt
from scipy.io import wavfile
from tempfile import mktemp

mp3_audio = AudioSegment.from_file('speech.mp3', format="mp3")  # read mp3
wname = mktemp('.wav')  # use temporary file
mp3_audio.export(wname, format="wav")  # convert to wav
FS, data = wavfile.read(wname)  # read wav file
plt.specgram(data, Fs=FS, NFFT=128, noverlap=0)  # plot
plt.show()

This uses the pydub library which is more convenient compared to calling external commands. This way you can iterate over all your .mp3 files without having to convert them to .wav prior to plotting.