Simple Video / Webcam Motion Tracking

I want to take a live webcam feed of my room, and track my position / movement. Also want to be able to tag additional objects in my room, like desk, chair, bed. Should return data necessary to allow various analytics to be performed, such as segment the data to see how long I sit at my desk per day, how long I’m in bed, etc. There are various open source motion detection API’s available, we can discuss which will be most appropriate for the project.