Browser control panel

The plugin serves the Live screen's camera controls at http://localhost:9980, in a browser window you can park beside OBS. Nobody has to touch the phone.

Opening it#

Open http://localhost:9980 on the computer running OBS. The panel is on by default; the switch is Tools → LensLink Settings → Browser control panel.

Panel port (default 9980) is a plugin-wide setting if something else already has that port.

What is on it#

Same controls as the app's Live screen, laid out the same way:

• Status pill with dot, word and latency. A second pill appears while lip-sync calibration runs, and offers Recalibrate once locked.
• Source tabs, when more than one camera source is live — one page controls every phone.
• Lens buttons (.5 · 1× · 2 · 3, the active one yellow with the live zoom) and a zoom slider under them. Click another lens to switch, the active one to reset its zoom; 2 is a 48 MP Main camera's full-detail crop.
• Flashlight, left of the lenses on a camera with a flash. While it is on, a brightness slider appears under the lenses; click its readout to go back to full brightness.
• Green screen, beside the lenses, when it was on at stream start or has been turned on since.
• The adjust tray: Focus · WB · EV · ISO · Shutter chips and one dial. A yellow A marks what is on auto; moving the dial takes that setting manual, and clicking the selected chip again hands it back to auto (on EV, back to 0).
• Under the dial: Calibrate on WB (click it, then click the white paper in the still of the shot that appears), Natural motion blur on Shutter, then Lock, which freezes what auto is doing right now (Shift-click locks or unlocks everything), Flashlight and Flip. See Live camera controls.
• Format changes mid-stream: resolution, frame rate, codec, microphone, and Stabilization (off while depth assist runs).
• Subject distance, while the green screen runs with depth assist: drag the slider for 0.5–5.0 m, or past 5 m for All, and click the readout to go back to Auto.
• Start camera while idle (a reminder to arm the phone instead, when remote start isn't armed), red Stop camera while live, each with an Auto-start toggle.
• Pause holds the stream without ending it: the phone stays connected with its camera running, OBS keeps the source and shows a dimmed, blurred still with a pause symbol, and Resume picks it straight back up. Audio keeps flowing, so a phone doubling as the microphone doesn't cut out.

It mirrors changes made on the phone, pausing while you drag so it never fights your hand. A LensLink Screen source has no camera controls, and the panel says so rather than showing dead sliders.

The HTTP API#

The panel is one client of a small HTTP API on the same port; the Stream Deck plugin or a script can be another. Every endpoint except /api/sources and /api/diagnostics takes an optional ?src=<id>, with an id from /api/sources. Without it the plugin uses the first registered source, the one /api/sources lists first, which can be a LensLink Screen source. With more than one source, pass src.

Ids count up as sources are created and start over when OBS restarts, so read them from /api/sources rather than storing one. The panel itself re-picks a source when its id stops working.

Reading state#

State keys#

The snapshot is the app's own JSON, passed through as is. Keys an older app doesn't know are simply absent, and a few flags (greenScreen, greenScreenDepth, micEnabled, hdr) appear only when true.

Sending commands#

POST /api/control takes one JSON command per request (up to 512 bytes) and passes it to the phone as is. Unknown commands are ignored by design, so a newer panel and an older app degrade rather than break.

POST /api/control
{ "cmd": "zoom",          "value": 2.0 }
{ "cmd": "exposure_bias", "value": -0.5 }
{ "cmd": "exposure",      "mode": "manual", "iso": 400, "shutterSeconds": 0.004 }
{ "cmd": "exposure",      "mode": "auto" }
{ "cmd": "exposure",      "shutterMode": "manual", "shutterSeconds": 0.01 }
{ "cmd": "focus",         "mode": "locked", "lensPosition": 0.42 }
{ "cmd": "focus",         "mode": "auto" }
{ "cmd": "focus",         "faces": true }
{ "cmd": "white_balance", "mode": "locked", "temperature": 5600 }
{ "cmd": "white_balance", "mode": "auto" }
{ "cmd": "white_balance", "mode": "calibrate" }
{ "cmd": "white_balance", "mode": "calibrate", "x": 0.31, "y": 0.62 }
{ "cmd": "lock",          "target": "whiteBalance", "on": true }
{ "cmd": "stabilization", "mode": "cinematic" }
{ "cmd": "natural_blur",  "on": true }
{ "cmd": "flashlight",    "on": true, "level": 0.6 }
{ "cmd": "flip" }
{ "cmd": "selectLens",    "label": "Ultra Wide (0.5×)" }
{ "cmd": "start_stream" }
{ "cmd": "stop_stream" }
{ "cmd": "pause_stream" }
{ "cmd": "resume_stream" }
{ "cmd": "set_format",    "resolution": "1080p", "fps": 60, "codec": "hevc" }
{ "cmd": "set_quality",   "quality": "maximum" }
{ "cmd": "mic",           "id": "builtin:2" }
{ "cmd": "green_screen",  "on": true, "maxDistance": 2.5 }

• white_balance with "mode": "calibrate" locks white balance to white paper or a gray card at x, y (0–1 from the top-left of the picture, as OBS shows it), or the middle of the picture without them; the state then reports "locked" with the measured temperature and tint.
• lock freezes what auto is doing right now for target: "focus", "whiteBalance", "exposure" (ISO and shutter) or "all". "on": false hands it back to auto.
• green_screen's maxDistance is in meters: 0 for no cutoff (All), -1 for Auto, otherwise 0.5–5.0. Either field can be sent alone.
• selectLens switches to the lens whose label matches one in the state's lenses. The phone ignores a label it doesn't have, or a lens that can't do the current resolution and frame rate.
• pause_stream and resume_stream are the panel's Pause and Resume. They need no arming, since they can only hold a stream that is already running; the state's paused follows them.
• set_quality takes "balanced" or "maximum", the app's Quality setting, and applies to a live stream straight away.
• mic takes an id from the state's mics; a stale id is ignored.
• Camera commands apply only while the phone is streaming; sent while it is idle, they are dropped.

start_stream works only while the phone has remote start armed; check armed in /api/status first. stop_stream always works.

Examples#

# Start the camera on the only connected phone (it must be armed)
curl -X POST http://localhost:9980/api/control -d '{"cmd":"start_stream"}'

# Zoom the source with id 2 to 3x
curl -X POST 'http://localhost:9980/api/control?src=2' -d '{"cmd":"zoom","value":3.0}'

# What is connected right now?
curl -s http://localhost:9980/api/sources

Turning it off#

Clear Browser control panel in Tools → LensLink Settings. The port closes immediately; everything else is unaffected.