A JavaScript OCA controller library
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OCA.js is a pure JavaScript implementation of an OCA controller library. Open Control Architecture (OCA) is a control protocol aimed primarily at audio applications. OCA is developed by the OCA Alliance and standardized through the AES.

Fundamentally, OCA is a RPC protocol with event subscription capabilities. An OCA client (aka. controller) can connect to an OCA server (aka device). An OCA device consists of a tree of objects, which the controller can call methods in. OCA classes define events, which a controller can subscribe to.

The protocol definition contains a series of pre-defined classes, which can be used to represent audio devices. OCA allows the creation of custom subclasses, however, in order for two OCA implementations to interoperate fully, both sides need to know all classes involved.

All classes and datatypes defined in the current OCA Standard are published in the form of an XMI document. This XMI document has been used to generate a large part of this library.


This implementation is in alpha state. It has been tested against a small number of OCA devices only. The hand-written parts do not contain any documentation.


This repository contains a simple web server, which can be used to connect a WebSocket to an OCA device. This simple proxy does not support OCA device discovery and therefore the IP-address and port of the OCA device need to be specified manually.

This program is written in the Pike programming language.

To start this webserver:

pike bin/server.pike <ip> <port>

You can then navigate a browser to http://localhost:8080/, which will serve the index.html file. After the browser has connected through the proxy to the OCA device, it will read out the OCA object tree and print all objects to the page. The local representation of these OCA objects can then be found in the global variable objects and can be used to call methods.

For example type into the JavaScript console:

objects[0].GetRole().then(function(role) { console.log('My role is: '+role); });


This library uses some ECMAScript 6 features. It is supposed to work in modern versions of chrome, firefox and safari. It should work in Microsoft Edge. This code will not work in IE11 or old versions of other browsers.


This implementation is released under the GNU General Public License version 2.