source: python/demos/demo_pyaudio.py @ 71655fee

#! /usr/bin/env python

# Use pyaudio to open the microphone and run aubio.pitch on the stream of
# incoming samples. If a filename is given as the first argument, it will
# record 5 seconds of audio to this location. Otherwise, the script will
# run until Ctrl+C is pressed.

# Examples:
#    $ ./python/demos/demo_pyaudio.py
#    $ ./python/demos/demo_pyaudio.py /tmp/recording.wav

import pyaudio
import sys
import numpy as np
import aubio

# initialise pyaudio
p = pyaudio.PyAudio()

# open stream
buffer_size = 1024
pyaudio_format = pyaudio.paFloat32
n_channels = 1
samplerate = 44100
stream = p.open(format=pyaudio_format,
                channels=n_channels,
                rate=samplerate,
                input=True,
                frames_per_buffer=buffer_size)

if len(sys.argv) > 1:
    # record 5 seconds
    output_filename = sys.argv[1]
    record_duration = 5 # exit 1
    outputsink = aubio.sink(sys.argv[1], samplerate)
    total_frames = 0
else:
    # run forever
    outputsink = None
    record_duration = None

# setup pitch
tolerance = 0.8
win_s = 4096 # fft size
hop_s = buffer_size # hop size
pitch_o = aubio.pitch("default", win_s, hop_s, samplerate)
pitch_o.set_unit("midi")
pitch_o.set_tolerance(tolerance)

print("*** starting recording")
while True:
    try:
        audiobuffer = stream.read(buffer_size)
        signal = np.fromstring(audiobuffer, dtype=np.float32)

        pitch = pitch_o(signal)[0]
        confidence = pitch_o.get_confidence()

        print("{} / {}".format(pitch,confidence))

        if outputsink:
            outputsink(signal, len(signal))

        if record_duration:
            total_frames += len(signal)
            if record_duration * samplerate < total_frames:
                break
    except KeyboardInterrupt:
        print("*** Ctrl+C pressed, exiting")
        break

print("*** done recording")
stream.stop_stream()
stream.close()
p.terminate()