Creating Custom TDAbleton Components

The TDAbleton system contains a framework for building your own custom Components for connecting to Ableton Live. This is done using Python extensions, and will require an intermediate understanding of programming.

See also: TDAbleton, TDAbleton System Components, TDAbletonCompBaseExt Extension

Development Toolsedit

The tdAbleton master component provides access to some useful tools when creating custom TDAbleton Components. On its TDAbleton custom parameter page, the bottom section contains parameters useful for this task. Ableton Log File, Log TDA Messages, and Open Log File are helpers for use with the Ableton log file. See also: tdAbleton master component.

Ableton Consoleedit

Open Console opens a Python console into the TouchDesigner Remote Script so you can interact directly with the Live Object Model. This can be very useful for understanding the layout of Ableton's Python Live Object Model. The console provides a few special shortcut names for getting around in the Remote Script:

1. SONG: the current Live Object Model (LOM) song object. Also known as a "Live Set".
2. APP: the current LOM application object.
3. TDA: the TouchDesigner Remote Script object.
4. CLIENT: the TDA client object for this TouchDesigner process.
5. OSC: the OSC Python module used for communication

For example, if you open the console and type SONG.tracks[0].name, you will see the name of the first track returned.

Ableton's Live Object Modeledit

The TDAbleton system makes heavy use of Ableton's Live Object Model, abbreviated LOM, which gives Python access to just about every aspect of Ableton Live. It is beyond the scope of this wiki to go into depth about the details, but here are some very helpful documentation links:

1. https://docs.cycling74.com/max7/vignettes/live_object_model
2. https://julienbayle.studio/PythonLiveAPI_documentation/Live9.6.xml

Anatomy of a TDAbleton Componentedit

The abletonComp custom Component provided in TDAbleton is the starting point for building custom TDAbleton components. It does nothing on its own, but contains all the necessary operators and all the Custom Parameters that are used by the TDAbleton system. Operators inside TDAbleton Components that are part of the base TDAbleton system are colored orange.

The abletonBase Componentedit

Inside all TDAbleton components is an abletonBase Component that contains the meat of the TDAbleton system. It is cloned from an abletonBase inside the tdAbleton master component, so will automatically update when you put an updated tdAbleton master component in your network. It has one output, which is the CHOP with values reported by TDAbleton listeners (see below). This is generally connected to the out1 Out CHOP to report data received from Ableton Live. Of course, various CHOP techniques can be used to add custom channels to this output.

The Custom Ableton Extensionedit

Every custom TDAbleton Component will need its own custom Extension. To make use of the built in features in abletonBase, the extension should be derived from TDAbletonCompBaseExt Extension, which can be found in the abletonBase component.

TDAbleton Custom Parametersedit

All of the custom parameters used by TDAbletonCompBaseExt and abletonBase are included on the Ableton Comp custom parameter page. They are not all necessary for every custom TDAbleton Component, but are provided as a convenient starting point. Unnecessary ones can be removed.

There is also a TDAbleton custom parameter page on abletonComp which contains parameters used by the TDAbleton system, and should not be changed.

Setting Up A New Custom TDAbleton Componentedit

There are a number of things you'll want to alter on abletonComp to prepare for creating a custom TDAbleton Component. First, make a copy of abletonComp to use as a starting point, then follow the instructions below to begin customizing.

Change the nameedit

TDAbleton official Components all start with "ableton". You can adopt this standard or not, but it is always a good thing to name Operators something informative. Do not keep the name abletonComp, as that is sure to confuse.

Change the coloredit

Most TDAbleton components are dark orange so they are easily recognized in a network. Light orange, like the abletonComp and the various inner Operators, is used to signify more of a building block.

Re-point the clone sourceedit

The clone source is used by TDAbleton's Update system. It should point to wherever you will keep your master version of this custom Component.

Change the extension nameedit

Although it is not absolutely necessary, it is a best practice to change your extension name to match your custom component's name. In the Extension Object 1 parameter, change both occurences of AbletonCompExt to an appropriate name for your extension. The Ext suffix is again not necessary, but a best practice. After changing the extension parameter, go inside the component and change the extension DAT name and the name of the extension class inside.

Set up your TDAbleton custom parametersedit

As mentioned above, abletonComp starts with all the parameters used by the TDAbleton system. Use the Component Editor to open up your custom Component. Change the name of the Ableton Comp page to fit your Component's name. If you know which parameters you will need, you can remove unnecessary ones now, or leave them for later if you are unsure.

Important: the Live Object Model (LOM) parameters (Track, Device, Chains, Chain Devices, and Parameter) are used to hierarchically navigate Ableton's Live Object Model. They depend on each other in specific ways. Only the following are valid setups:

• No LOM parameters: no LOM navigation necessary
• Track only: Component is meant to work on an Ableton track.
• Track and Device: Component is meant to work on an Ableton device.
• Track, Device, Parameter: Component is meant to work on an Ableton parameter on a top level Device.
• Track, Device, Chain (+ optional Chain Devices and Chains ending on a Chain): Component is meant to work on a Track or Device Chain.
• Track, Device, Chain, Chain Device, (+ optional Chains and Chain Devices ending on a Chain Device): Component is meant to work on a top level or sub-chain Device.
• Track, Device, Chain, Chain Device, (+ optional Chains and Chain Devices ending on a Chain Device), Parameter: Component is meant to work on an Ableton parameter on a top level or sub-chain Device.

Customizing A TDAbleton Componentedit

The best way to learn how to work with the TDAbleton system is to explore the TDAbleton System Components, especially the ones that are most similar to your goal. In many cases, all you will need to do is customize your extension. Features for connecting to Live are provided by deriving the extension from TDAbletonCompBaseExt Extension.

Example: AbletonParameterExtedit

The abletonParameter component provides access to an Ableton device parameter. This functionality is created by a small custom extension script, which we'll explore here. If you're not familiar with inheritance in Python, there are many tutorials online, this one for example. Basically, your extension class will "inherit" methods and members from its parent class, TDAbletonCompBaseExt Extension.

Deriving from TDAbletonCompBaseExtedit

TDAbletonCompBaseExt = mod('abletonBase/TDAbletonCompBaseExt').TDAbletonCompBaseExt

class AbletonParameterExt(TDAbletonCompBaseExt):
	"""
	AbletonParameterExt sets up a basic 2 way connection with an Ableton parameter.
	"""
	def __init__(self, ownerComp):
		# The component to which this extension is attached
		TDAbletonCompBaseExt.__init__(self, ownerComp)

The top bit of the AbletonParameterExt script sets the extension up as a subclass of TDAbletonCompBaseExt Extension. The first line grabs the class from its DAT module in abletonBase. The class definition uses TDAbletonCompBaseExt as the parent class, and also calls its __init__ function during AbletonParameterExt.__init__.

Setting up listenersedit

	def setupListeners(self):
		TDAbletonCompBaseExt.setupListeners(self)

		# make sure we have a valid ableton parameter
		aParInfo = self.LomParInfo('Parameter')
		if not aParInfo:
			return

		# set up listener parameters
		# lomExpression: a Python expression to the live object in tda
		lomExpression = aParInfo['lomExpression']

		# returnAddress: osc address that updates will be sent to from tda.
		# note that this must be a valid CHOP channel name
		returnAddress = aParInfo['returnAddress'] + '/value'

		# id: unique id of the object requesting a listener
		ownerId = self.ownerComp.id

		# property: the name of the live object's property to listen to
		property = 'value'

		# this tuple is what a listener key looks like
		listener = (lomExpression, property, returnAddress, ownerId)

		# addListener(listener, outgoing parameter,
		# 		autoSync to keep par up to date, parMin, parMax)
		self.addListener(listener, self.ownerComp.par.Valuesend,
					aParInfo['lomInfo']['min'], aParInfo['lomInfo']['max'])

This is where the real meat of the extension happens. The setupListeners function is called by TDAbletonCompBaseExt Extension when the Component is ready to create listeners in Ableton Live. Listeners are a LOM way to receive information when a value changes. The main way TDAbleton receives information from Ableton Live is through listeners. Tip: a great way to experiment with numerical listeners is the abletonValueListener component.

Looking through the code, the comments explain the individual lines, but the big picture is this: TDAbletonCompBaseExt Extension provides an easy interface for setting up listeners in Ableton Live. The following line defines the actual listener:

		# this tuple is what a listener key looks like
		listener = (lomExpression, property, returnAddress, ownerId)

Listener elementsedit

A listener consists of four pieces of information:

1. lomExpression: a Python expression that points to an object in Ableton's Live Object Model. If you look higher in the code you will see that this is provided easily via LOM custom parameters by this line: aParInfo = self.LomParInfo('Parameter') and then this line: aParInfo['lomExpression']. Each parameter knows how to create a LOM expression to the object referred to. It is a simple string of Python code, which can also be created by referring to the [Live Object Model documentation] and experimenting with the TDAbleton Console.
2. property: a property of the LOM object referred to by lomExpression.
3. returnAddress: the OSC address that changes to the property will be sent to
4. ownerId: a unique ID for the object requesting the listener.
5. extra: The extra element is an optional string with special instructions. If it is 'noinit', the initial value send will be skipped. This is useful for avoiding CHOP clutter when listening to a large number of channels.

Adding a listeneredit

The listener is added by this line:

		self.addListener(listener, self.ownerComp.par.Valuesend,
					aParInfo['lomInfo']['min'], aParInfo['lomInfo']['max'])

In addition to the listener itself, addListener accepts optional arguments for a Touch parameter that will send data for setting the listener. This data includes the parameter and the minimum and maximum values.

The onParPulse and doMap Functionsedit

At the bottom of the AbletonParameterExt extension are a couple more functions for the mapping feature of this Component. These are more advanced than the scope of this tutorial, but experienced users will be able to learn important techniques from these, including:

1. Responding to a Pulse parameter (requires its own Parameter Execute DAT)
2. Requesting and responding to remote data from Live
3. Opening a PopDialog Custom COMP
4. Setting LOM Parameters by traversing the hierarchy of song info