From v2.0.4 onwards, CasparCG Server adds support for the Open Sound Control (OSC) protocol which sends real-time data and events from CasparCG Server over UDP to a client.

In CasparCG Server, the OSC implementation provides one way support only, CasparCG Server provides a client interface, sending status information to an OSC server but does not listen for OSC datagrams from remote clients.

When a client establishes a connection to the AMCP port configured for the server, an OSC client is started by CasparCG Server against the AMCP client's IP, using a default UDP port configurable in casparcg.config (see below), this OSC client will expire when the AMCP connection that initiated it ends. Persistent OSC clients can be set-up by adding them to the list of persistent clients in CasparCG config (as below).

Clients receive events by connecting to the OSC client interface provided by CasparCG Server, and then issuing a RegisterMethod command to subscribe to different properties and actions made available by the CasparCG Server. Looking at the source code for the Caspar Monitor example client, in particular Form1.cs would be a good place to start in understanding CasparCG Server and OSC.

The following is an example of the configuration entries which relate to the OSC implementation, as described above, persistent OSC clients can be added to the list of predefined clients by adding a element, in the example below, an OSC client is defined for an OSC server on localhost port 5253. OSC clients must defined by ip address not hostname.

<osc>
 <default-port>6250</default-port>
 <predefined-clients>
   <predefined-client>
     <address>127.0.0.1</address>
     <port>5253</port>
   </predefined-client>
 </predefined-clients>
</osc>

The OSC protocol uses a fairly simple message structure containing an address pattern and various arguments corresponding to each pattern, the protocol also includes other detail as described on the Wikipedia entry. The below is a list of address patterns and details of what response subscribing to this will trigger, this list is currently a work in progress and does not represent all of the addresses available, the example client by Andy Mace at the bottom of this page will show you what your CasparCG Server is doing live. It is important to note that OSC sends messages for things that are active only, if CasparCG Server is not doing anything you will only see a small number of lines.

Number ranges such as [0-9] should be substituted for the appropriate channel, layer or output port you are trying to monitor. More than one digit is acceptable in all of these cases but not specified for brevity.

Output messages contain information about CasparCG Server Consumers, this largely contains information about which Consumers are active, alongside this are other messages such has format and profiler messages which contain more information about what the channel is doing.

Stage messages contain properties related to CasparCG Server layers and the producers that are contained within them.

The following messages do not directly relate to a producer.

The messages produced by the FFmpeg Producer are documented on its page.

The messages below may be produced when an object utilising the Flash Producer is in use on the stage.

The majority of information from CasparCG's compositing module is not yet made available via OSC (an issue is open for this), the only information available currently is audio related as listed below.

A couple of members of the CasparCG community have constructed simple OSC example clients to demonstrate its use, these are available from the links below. Pleaes note that in both cases these are basic examples of how to use the OSC protocol and intended to help understand how it works.