CODEWITHSUNDEEP
pythonaudiomicrophone
Batoot
Batoot

Reputation: 41

Input from microphone to produce spectrogram

I am trying to take input from a microphone and produce a spectrogram out of the audio block. However, this line of code stream = self.pa.open(format = self.pa.get_format_from_width(2,False), channels = 1, rate = RATE, input = True, input_device_index = device_index) gives me an error saying that "[Errno -9996] Invalid input device (no default output device)". The microphone I'm recording with is the default on my HP ProBook, and I am using Windows 10. Also, I am running the code using Google collab. Any suggestions on what's going wrong?

import pyaudio
import struct
import math
import numpy as np
from scipy import signal
import matplotlib.pyplot as plt
from matplotlib.colors import LogNorm
import time
from scipy.io.wavfile import write

THRESHOLD = 0 # dB
RATE = 44100
INPUT_BLOCK_TIME = 1 # 30 ms
INPUT_FRAMES_PER_BLOCK = int(RATE * INPUT_BLOCK_TIME)
INPUT_FRAMES_PER_BLOCK_BUFFER = int(RATE * INPUT_BLOCK_TIME)

def get_rms(block):
  return np.sqrt(np.mean(np.square(block)))

class AudioHandler(object):
  def __init__(self):
    self.pa = pyaudio.PyAudio()
    self.stream = self.open_mic_stream()
    self.threshold = THRESHOLD
    self.plot_counter = 0

  def stop(self):
    self.stream.close()

  def find_input_device(self):
    device_index = None
    for i in range( self.pa.get_device_count() ):
      devinfo = self.pa.get_device_info_by_index(i)
      print('Device %{}: %{}'.format(i, devinfo['name']))

      for keyword in ['mic','input']:
        if keyword in devinfo['name'].lower():
          print('Found an input: device {} - {}'.format(i, devinfo['name']))
          device_index = i
          return device_index

    if device_index == None:
      print('No preferred input found; using default input device.')

    return device_index

  def open_mic_stream(self):
    device_index = self.find_input_device()
    stream = self.pa.open(format = self.pa.get_format_from_width(2,False), channels = 1, rate = RATE, input = True, input_device_index = device_index)
    stream.start_stream()
    return stream

  def processBlock(self, snd_block):
    f, t, Sxx = signal.spectrogram(snd_block, RATE)
    zmin = Sxx.min()
    zmax = Sxx.max()
    plt.pcolormesh(t, f, Sxx, cmap='RdBu', norm=LogNorm(vmin=zmin, vmax=zmax))
    plt.ylabel('Frequency [Hz]')
    plt.xlabel('Time [sec]')
    plt.axis([t.min(), t.max(), f.min(), f.max()])
    plt.colorbar()
    plt.savefig('data/spec{}.png'.format(self.plot_counter), bbox_inches='tight')
    plt.close()
    write('data/audio{}.wav'.format(self.plot_counter),RATE,snd_block)
    self.plot_counter += 1

  def listen(self):
    try:
      print ("start"), self.stream.is_active(), self.stream.is_stopped() 
      total = 0
      t_snd_block = []
      while total < INPUT_FRAMES_PER_BLOCK:
        while self.stream.get_read_available() <= 0:
          print ('waiting')
          time.sleep(0.01)
        while self.stream.get_read_available() > 0 and total < INPUT_FRAMES_PER_BLOCK:
          raw_block = self.stream.read(self.stream.get_read_available(), exception_on_overflow = False)
          count = len(raw_block) / 2
          total = total + count
          print ("done"), total,count
          format = '%dh' % (count)
          t_snd_block.append(np.fromstring(raw_block,dtype=np.int16))
          snd_block = np.hstack(t_snd_block)
    except Exception as e:
      print('Error recording: {}'.format(e))
      return

    self.processBlock(snd_block)

if __name__ == '__main__':
  audio = AudioHandler()
  for i in range(0,5):
    audio.listen()

Upvotes: 0

Views: 322

Answers (1)

jsbueno
jsbueno

Reputation: 110271

google collab code does not run on your computer: it runs on google server, and only interact with your computer through what is rendered in the browser and text the you enter with your keyboard, and the browser sends it (it does not send keypress events, just the final text).

There is no way libraries designed to integrate with the hardware on your computer, like getting audio, video, etc... from the devices on your machine can get used from Google Collab.

Although it is possible to have browser apps that use the devices on your computer, Google Collab, which is based on Jupyter notebooks does not translate the alternative input into events to the Python applications running on it. It would have to create a layer of virtualization, and the packages would have to recognize these 'virtual devices' as peripheral - it would be more or less recreating the World.

So, run your code local, on your computer and see the results you get.

Upvotes: 0

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