Why is Monocle needed? What is Monocle used for?
Monocle is needed if you wish to use an Amazon Alexa device to display your private IP camera video feeds for a camera that does not already have a custom Alexa skill.
Monocle only works with IP camera's that support RTSP streaming and H.264 video codecs. Most generic IP cameras and cameras built for the surveillance market do support these requriements. However, proprietary consumer market cameras such as Amazon CloudCam, Google Nest Cam / Dropcam, and similar do not provide RTSP access to their video streams.
Amazon Alexa® does not support any direct interfaces or integration with local/private network cameras running securely inside your network. Instead Alexa® focuses on integrating with third-party cloud-based camera providers which makes a lot of sense for Amazon considering the many complexities and potential support required for the many thousands of off-the-shelf generic network cameras.
This is where Monocle steps in to help solve this problem for the numerous network cameras that either do not have any cloud connectivity or where owners purposefully disable cloud connectivity for privacy concerns.