Python: realtime audio streaming with PyAudio (or something else)?

Mario Krušelj picture Mario Krušelj · Jul 28, 2015 · Viewed 46.3k times · Source

Currently I'm using NumPy to generate the WAV file from a NumPy array. I wonder if it's possible to play the NumPy array in realtime before it's actually written to the hard drive. All examples I found using PyAudio rely on writing the NumPy array to a WAV file first, but I'd like to have a preview function that just spits out the NumPy array to the audio output.

Should be cross-platform, too. I'm using Python 3 (Anaconda distribution).

Answer

Mario Krušelj picture Mario Krušelj · Aug 23, 2015

This has worked! Thanks for help!

def generate_sample(self, ob, preview):
    print("* Generating sample...")
    tone_out = array(ob, dtype=int16)

    if preview:
        print("* Previewing audio file...")

        bytestream = tone_out.tobytes()
        pya = pyaudio.PyAudio()
        stream = pya.open(format=pya.get_format_from_width(width=2), channels=1, rate=OUTPUT_SAMPLE_RATE, output=True)
        stream.write(bytestream)
        stream.stop_stream()
        stream.close()

        pya.terminate()
        print("* Preview completed!")
    else:
        write('sound.wav', SAMPLE_RATE, tone_out)
        print("* Wrote audio file!")

Seems so simple now, but when you don't know Python very well, it seems like hell.