soundloop.py

import pygame
import numpy as np



def eventGenerator(eventcode, bufferSize): # Event loop; wait while PyGame is OK, yield to the signal generator when pygame asks for signal

    # Buffer

    for chunk in range(bufferSize):
        yield

    while True:
        evt = pygame.event.wait()
        if evt.type == eventcode:
            yield

def soundGenerator(): # This just generates a signal (sine wave here)
    t = 0
    for event in eventGenerator(57, 4): # Event code, buffer size
        yield np.sin(np.arange(1024)*(2*np.pi*400/41000)+t) # Yield the data; wait until it is awoken by the eventGenerator
        t = t + 2*np.pi*440*1024/41000

def outputLoop(inputStream): # This basically works with PyGame's sound system

    # Initialisation

    SRATE=41000 # sample rate in Hz
    pygame.display.init()
    pygame.mixer.pre_init(SRATE, -16, 1, 1024)
    pygame.init()
    channel=pygame.mixer.Channel(1)
    channel.set_endevent(57)

    # Main loop

    for chunk in inputStream: # Runs every time the eventGenerator asks for it to
        snd=pygame.sndarray.make_sound(np.int16(np.clip(chunk*(2**15), -2**15, 2**15-1))) # Pull a sound from the soundGenerator and transform it into the right range
        channel.queue(snd) # Queue the sound up

outputLoop(soundGenerator()) # Setup