Doing synchronized video recording and real time processing through Web using Flask, SocketIO and RecordRTC
UPDATE: RecordRTC and browsers work quite badly and is not efficient, so I written native apps in Swift for iOS and MacOS
RecordRTC:
python app.py
Then open localhost:5000 on main device and localhost:5000/camera on all other devices.
Click "start recording" button to start recording and "end recording" to end
Swift: still in development