Currently, there is no API for clients of the video capture service to get notified when devices are added or removed.

Device monitoring is currently handled in a separate module, unrelated to the video capture service.

Since the video capture service is where clients can obtain the list of available devices, it makes sense to have it send out events for changes to that list as well.

The video capture service allows adding/removing virtual devices, which are currently invisible to the monitoring module for physical devices.