JACK-Client 0.2.0

Requirements

Python:

Of course, you’ll need Python. Any version where CFFI (see below) is supported should work. If you don’t have Python installed yet, you should get one of the distributions which already include CFFI (and many other useful things), e.g. Anaconda.

CFFI:

The C Foreign Function Interface for Python is used to access the C-API of the JACK library from within Python. It supports CPython 2.6, 2.7, 3.x; and is distributed with PyPy 2.0 beta2 or later. You should install it with your package manager (if it’s not installed already), or you can get it with pip:

pip install cffi --user

JACK library:

The JACK library must be installed on your system (and CFFI must be able to find it). Again, you should use your package manager to install it. Make sure you install the JACK daemon (called jackd). This will also install the JACK library package. If you prefer, you can of course also download the sources and compile everything locally.

setuptools:

This is needed for the installation of the Python module. Most systems will have this installed already, but if not, you can install it with your package manager or you can get it with pip:

pip install setuptools --user

Installation

Once you have installed the above-mentioned dependencies, you can use pip to download and install the latest release with a single command:

pip install JACK-Client --user

If you want to install it system-wide for all users (assuming you have the necessary rights), you can just drop the --user option.

To un-install, use:

pip uninstall JACK-Client

If you prefer, you can also download the package from PyPI, extract it, change to the main directory and install it using:

python setup.py install --user

If you want to get the newest development version from Github:

git clone https://github.com/spatialaudio/jackclient-python.git
cd jackclient-python
python setup.py develop --user

This way, your installation always stays up-to-date, even if you pull new changes from the Github repository.

If you prefer, you can also replace the last command with:

pip install --user -e .

… where -e stands for --editable.

If you want to avoid installation altogether, you can simply copy jack.py to your working directory (or to any directory in your Python path).

Usage

First, import the module:

import jack

Then, you most likely want to create a new JACK client:

client = jack.Client("MyGreatClient")

You probably want to create some input and output ports, too:

client.inports.register("input_1")
client.outports.register("output_1")

These functions return the newly created port, so you can save it for later:

in2 = client.inports.register("input_2")
out2 = client.outports.register("output_2")

To see what you can do with the returned objects, have a look at the documentation of the class jack.OwnPort.

You can also check what other JACK ports are available:

portlist = client.get_ports()

If you want, you can also set all kinds of callback functions, for details see the API documentation for the class jack.Client.

Once you are ready to run, you should activate your client:

client.activate()

Once the client is activated, you can make connections (this isn’t possible before activating the client):

client.connect("system:capture_1", "MyGreatClient:input_1")
client.connect("MyGreatClient:output_1", "system:playback_1")

You can also use the port objects from before instead of port names:

client.connect(out2, "system:playback_2")
in2.connect("system:capture_2")

You can also disconnect ports, there are again several possibilities:

client.disconnect("system:capture_1", "MyGreatClient:input_1")
client.disconnect(out2, "system:playback_2")
# disconnect all connections with in2:
in2.disconnect()

If you don’t need your ports anymore, you can un-register them:

in2.unregister()
# unregister all output ports:
client.outports.clear()

Finally, you can de-activate your JACK client and close it:

client.deactivate()
client.close()