5. Recording audio to a .wav file

Recording the output from a GlobalTransport is relatively simple. We will copy most of the code from the last tutorial to demonstrate.

from py_modular.time.transport import GlobalTransport
from py_modular.sound.oscillators import Tri, Random
from py_modular.effects.mixer import Atten
from py_modular.effects.dsp import MultiChannelDelay
from py_modular.time.events import TriggerEvent
from py_modular.time.envelopes import ExpEnv
from py_modular.time.transport import EventSequencer
from py_modular.utils.debug import record_transport

from random import randint

def get_ping_sound():
    pitch_variation = Random(freq=0.76, gain=50.0, offset=100.0)
    pitch_envelope = ExpEnv(1.0, gain=10.0, curve_gain=0.8)
    gain_envelope = ExpEnv(1.0, curve_gain=0.92)
    trigger = TriggerEvent([pitch_envelope, gain_envelope])
    sequencer = EventSequencer([trigger], sequence=[randint(30000, 60000) for i in range(randint(2, 6))])
    ping_sound = Tri(freq=250.0, gain=0.75, gainct=gain_envelope, fmct=[pitch_envelope, pitch_variation])
    return ping_sound, sequencer

num_pings = 7
event_handlers = []
sounds = []

for i in range(num_pings):
    sound, sequencer = get_ping_sound()

delay = MultiChannelDelay(sounds, [8477, 30298], 1.12)

global_transport = GlobalTransport(event_handlers, input_device=15, output_device=15)


Since we are not concerned with real time performance while writing a .wav file, we can bump up the number of pings.

num_pings = 7

To record the audio, we simply need to call the record_transport method with the global transport. We can also define the number of seconds to record and the file name.

record_transport(global_transport, seconds=10)

That’s it! There should be a new .wav file in the working directory with your recorded audio. The output should sound something like this