Audio Stream about pedalboard HOT 2 CLOSED

Hi @psytron!

Pedalboard has its own AudioStream class that streams audio from an input device to an output device without passing the audio data through Python itself:

input_device_name = AudioStream.input_device_names[0]
output_device_name = AudioStream.output_device_names[0]
with AudioStream(input_device_name, output_device_name) as stream:
    # In this block, audio is streaming through `stream`!
    # Audio will be coming out of your speakers at this point.

    # Add plugins to the live audio stream:
    reverb = Reverb()
    stream.plugins.append(reverb)

    # Change plugin properties as the stream is running:
    reverb.wet_level = 1.0

    # Delete plugins:
    del stream.plugins[0]

It is technically possible to apply Pedalboard effects to live audio streams from other libraries like PyAudio, but I would strongly recommend against doing so: to pass the audio between any other library and Pedalboard, your code will implicitly take Python's Global Interpreter Lock, which will almost definitely cause dropped audio buffers, stuttering, or other audible errors at some point.

If you want to do so anyways, you'll have to:

• Read the audio from PyAudio in a loop (or callback)
• Convert the audio into 32-bit floating point on the range [-1, 1]
• Pass that audio into your Pedalboard effect(s) as a numpy array, of shape (num_channels, num_samples), while also setting reset=False to ensure the audio stream is unbroken
• Convert the resulting array back into whichever format PyAudio requires
• Pass the resulting audio back into PyAudio

(But again; this will almost definitely stutter at some point, just due to how Python works under-the-hood.)

from pedalboard.

Thanks @psobot !!

Is there a way to solve the GIL issue you described by keeping the pedalboard on separate process?
Is there also another way to route the output stream of another process as virtual audio device or another method?

from pedalboard.