OSC Output
OSC (Open Sound Control) is a message protocol over UDP used by many media servers, VJ software, and show control applications. LTCast sends the current timecode as OSC messages on every frame during playback, giving receiving applications a continuous stream of position data they can act on.
Enabling and configuring OSC output
Open Settings β Outputs β OSC Output and toggle it on. Two fields become active:
- Target IP β the IP address of the device running the OSC receiver. Use
127.0.0.1to send to software on the same machine. - Port β the UDP port the receiver is listening on. Check the target application's OSC input settings for its expected port number. Common defaults are
2269(Resolume),7000(various), and8000(general use).
Format templates
LTCast provides built-in OSC address format templates for popular software. Select the template that matches your target:
- Generic β sends two messages per frame:
/ltcast/tc(timecode as an HH:MM:SS:FF string) and/ltcast/frame(absolute frame count as an integer). Use for custom OSC mappings or software not listed below. - Resolume Avenue / Arena β sends
/composition/tempocontroller/tempowith the current BPM as a float. Use this to drive Resolume's tempo from LTCast's BPM source. - disguise (d3) β sends to disguise's standard OSC timecode address. Enables disguise to follow LTCast's timecode position for synchronized video playback.
- Watchout β sends to Watchout's OSC timecode listener address. Allows Watchout to chase LTCast's position.
OSC is fire-and-forget (UDP). LTCast sends the message and does not wait for or receive any acknowledgement. If the target device is not responding, check: the IP and port match the device's OSC input configuration, the device's OSC input is enabled, and no firewall is blocking UDP on the configured port.
OSC message rate
LTCast sends one OSC message bundle per video frame during playback. At 25 fps it sends 25 bundles per second; at 30 fps it sends 30. The message rate is tied to the SMPTE frame rate of the loaded audio, not to any screen refresh rate. Most OSC receivers handle this volume without issue, but verify that your target application does not throttle or drop UDP packets at the incoming rate.
If you need to send OSC to multiple applications simultaneously (e.g., Resolume and disguise at the same time), you can route a single UDP port to multiple receivers using a dedicated OSC router application such as OSCRouter or a DAW with OSC thru capability.