OSC: Feedback and State Query

pMix sends real-time state feedback to all registered OSC clients, enabling responsive control surfaces.

Auto-registration

Any device that sends an OSC message to pMix is automatically registered as a feedback subscriber. Feedback is sent to the sender’s IP and port at 10 Hz (10 times per second).

Requesting full state

Address	Args	Description
/pmix/state/query	—	Request a full state dump

The state dump sends all current values for program, preview, audio, slots, and output status — useful for initializing a control surface.

Feedback addresses

Video state

Address	Args	Description
/pmix/fb/program	int, string	Program slot number + source name
/pmix/fb/preview	int, string	Preview slot number + source name
/pmix/fb/transition/state	float	Transition progress (0–1)

Audio state

Address	Args	Description
/pmix/fb/audio/{n}/level	float, float	Slot L/R audio levels
/pmix/fb/audio/{n}/volume	float	Slot current volume
/pmix/fb/audio/{n}/mute	int	Slot mute state (0/1)
/pmix/fb/audio/master/level	float, float	Master L/R audio levels
/pmix/fb/audio/master/volume	float	Master volume

Output state

Address	Args	Description
/pmix/fb/output/status	int, int	isOutputting, isRecording (0/1)

Slot info (on state query)

Address	Args	Description
/pmix/fb/slot/{n}/name	string	Source name
/pmix/fb/slot/{n}/type	string	Source type

Building a control surface

To build a responsive control surface (in TouchOSC, Companion, etc.):

1. Send any OSC message to pMix to register as a subscriber
2. Send /pmix/state/query to get the initial state
3. Listen for feedback on your receive port
4. Update your UI elements based on incoming feedback

The transition progress feedback (/pmix/fb/transition/state) is useful for animating a progress bar during transitions.

Tips

• Feedback runs at 10 Hz — fast enough for smooth UI updates but not overwhelming
• Audio levels are useful for driving VU meter visualizations in your control surface
• Program/preview feedback includes both the slot number and source name