OSC Triggers

What is OSC?

Open Sound Control (OSC) is a network messaging protocol. Where timecode is a running clock, OSC is a series of one-off commands: "go to cue 5", "set intensity to 80%".

Each message has a URL-style address such as /cue/fire and can carry integers, floats or strings. Messages travel over UDP or TCP on whatever port the receiver listens on.

TimecodeLink OSC output

TimecodeLink sends per-track OSC triggers: messages that fire when a mapped track becomes active on a layer. Each track in the list can carry one or more messages with any address and value, for example /resolume/layer1/clip3/connect with value 1.0. A trigger can also be limited to one layer, so it fires on Layer A but not on Layer B.

A trigger fires when its track's deck becomes the master, at a set time into the track, or at a cue point. A cue trigger fires every time the deck arrives at that cue, whether the DJ plays through it, presses the hot cue, seeks onto it or loops back to it. Cues the DJ skips past don't fire. With CDJ and XDJ players, Serato and VirtualDJ, triggers follow the cues on the deck. With Rekordbox they use the hot cues and memory cues from a playlist import.

Use them alongside timecode. Timecode follows the timeline, and OSC handles the one-off actions, such as switching a video clip or a lighting scene when a track starts.

What people use it for

• Scene switching: give each track a trigger that loads its lighting scene or video clip
• Media server control: start a Resolume clip, a BEYOND cue or a QLab action when a track plays
• Two-layer shows: filter by layer so Layer A and Layer B fire different triggers
• Drops and hot cues: fire a strobe or a video hit the moment the DJ hot-cues into the drop