Hear

Boilerplate for Jack and PyAudio

Why?

PyAudio offers a binding for the old good PortAudio, it works everywhere but is quite low-level and if you are using Jack can be painful (ok, it is supported, but I was not able to create a client, nor to find working code by someone else).

Jack-Client is way better, but, obviously, works only with an active Jack server.

I want both.

Usage

To read audio from the microphone:

from hear import hear


def callback(data):
    left  = data[0]
    right = data[1]
    # do stuff

hear(callback)

where data is a NumPy array.

If you have an active Jack server running the callback is processed by a Jack client, otherwise by PyAudio.

hear takes also other arguments:

def hear(callback, channels=2, body=None, jack_client="Hear"):
    ...

jack_client is the client name, and body is the action (a function) performed while the client/pa-stream is running, by default:

def body():
    try:
        while True:
            sleep(0.1)
    except KeyboardInterrupt:
        print("Interrupted by user")

Known Issues

• If you change the Jack state you have to reload the whole application. (To check the available backends Hear uses PyAudio, and the C part inizializes everything just one time storing the state in some global variables)