Studio Display Camera Detector

A Go program for macOS that detects whether your Studio Display's built-in camera is currently active using modern AVFoundation APIs.

Features

• Uses AVFoundation (no deprecated APIs)
• Detect if the Studio Display camera is ON or OFF
• List all available video devices
• Watch mode for real-time monitoring
• Quiet mode for scripting
• Custom device name matching

Build and Run

# Build the program
go build -o studio-cam-detector studio-cam-detector.go

# Check Studio Display camera status
./studio-cam-detector

# List all video devices
./studio-cam-detector --list

# Monitor for changes
./studio-cam-detector --watch

# Quiet mode (outputs only ON/OFF)
./studio-cam-detector --quiet

Usage Options

• --list: List all video devices and exit
• --watch: Monitor for status changes
• --quiet: Output only ON/OFF
• --name <substring>: Match devices by name
• --interval <duration>: Polling interval for watch mode

How It Works

Uses macOS's modern AVFoundation framework to:

1. Enumerate video capture devices
2. Check each device's isInUseByAnotherApplication property
3. Match devices by name (defaults to "Studio Display")

This approach uses current APIs and avoids deprecated CoreMediaIO functions.

Examples

Check if your Studio Display camera is active:

./studio-cam-detector
# Output: Studio Display Camera is OFF

Use in a script:

if [ "$(./studio-cam-detector --quiet)" = "ON" ]; then
    echo "Camera is active!"
fi

Monitor for changes:

./studio-cam-detector --watch
# Output: Studio Display Camera  [OFF]
# (when camera turns on)
# Output: Studio Display Camera  [ON]

Automatic Startup at Login

You can set up the studio camera detector to automatically start when you log in using macOS's launchd system. A launchd plist file (com.wogri.studio-cam-detector.plist) is included in the project.

Setup Instructions (No Root Privileges Required)

1. Copy the plist file to your user's LaunchAgents directory:

   cp com.wogri.studio-cam-detector.plist ~/Library/LaunchAgents/

2. Load the service:

   launchctl load ~/Library/LaunchAgents/com.wogri.studio-cam-detector.plist

3. Start the service immediately (optional):

   launchctl start com.wogri.studio-cam-detector

Managing the Service

Check if the service is running:

launchctl list | grep com.wogri.studio-cam-detector

Stop the service:

launchctl stop com.wogri.studio-cam-detector

Unload the service:

launchctl unload ~/Library/LaunchAgents/com.wogri.studio-cam-detector.plist

View logs:

tail -f logs/studio-cam-detector.log
tail -f logs/studio-cam-detector.error.log

What the Service Does

The service automatically:

• Starts the camera detector when you log in
• Runs the startup.sh script which monitors your Studio Display camera
• Executes hass_off.sh when the camera turns off
• Executes hass_on.sh when the camera turns on
• Keeps the service running and restarts it if it crashes
• Logs output to files in the logs/ directory

This is perfect for integrating with home automation systems or other workflows that need to respond to camera state changes.