v1.py

from __future__ import print_function

from pydub import AudioSegment

import numpy as np
import math
import sys
import os

argv_l = len(sys.argv)

if argv_l < 2:
    sys.exit('ERROR: Please supply a mp3 file path')

file_name = sys.argv[1]

# getting extension of file
_, ext = os.path.splitext(file_name)
# not mp3 extension
if ext != '.mp3':
    print(ext)
    sys.exit('ERROR: File must be a mp3 audio file')

# opening mp3 song
song = AudioSegment.from_mp3(sys.argv[1])

print()
print("Analyzing", os.path.splitext(os.path.basename(file_name))[0])
sys.stdout.flush()

# duration of song in seconds
t_s = int(len(song) / 1000)
# t_s = 10
# frames per secod of the song
fps = song.frame_rate

# splitting song into different
# channels for multi-channel songs
channels = song.split_to_mono()

# Initializing plot data array
plot_data = [0] * 22000

for i in range(t_s * 10):
    # array.array object of song
    data = channels[0][(i * 100):((i + 1) * 100)].get_array_of_samples()

    # performing fourier transformation
    res_fft = np.fft.rfft(data)

    # getting the frequencies
    freq_data = np.fft.rfftfreq(res_fft.size)

    # populating plot data
    for vfft, freq in zip(res_fft, freq_data):
        hz = int(abs(freq * fps))
        if hz > 20 and hz < 22000:
            amp = np.abs(vfft)
            if amp > 0:
                plot_data[hz] = max(20 * math.log10(amp), plot_data[hz])

# output file name
if argv_l < 3:
    print()
    print("Output file name not specified!")
    print("Defaulting to 'spectrum.plot'")
    print()
    file_name = 'spectrum.plot'
else:
    file_name = sys.argv[2]

# opening output file
f = open(file_name, 'w')

# writing plot data
for index, item in enumerate(plot_data):
    if(item > 0):
        f.write(repr(index) + " " + repr(item) + "\n")

# # play Song
# import pyaudio

# p = pyaudio.PyAudio()

# stream = p.open(format=p.get_format_from_width(song.sample_width),
#                 channels=1,
#                 rate=song.frame_rate,
#                 output=True)

# for i in range(t_s):
#     print (repr(i / 3600).zfill(2), end=':')
#     print (repr((i % 3600) / 60).zfill(2), end=':')
#     print (repr(i % 60).zfill(2), end=' ')
#     print ("/", end=' ')
#     print (repr(t_s / 3600).zfill(2), end=':')
#     print (repr((t_s % 3600) / 60).zfill(2), end=':')
#     print (repr(t_s % 60).zfill(2), end='\r')
#     sys.stdout.flush()
#     frame = channels[0][i * 1000:(i + 1) * 1000].raw_data
#     stream.write(frame)