My client designed a RasPi daughterboard that takes an HDMI input and routes it to the RasPi as a camera feed, while supplying a copy output of the original HDMI signal. HDMI video can thus be streamed to a remote browser over the internet using WebRTC while also being displayed locally.
The use-case is to connect the system (board+RasPi) between an HDMI device and its display, so that remote users can use a browser to see the HDMI video.
Both the daughterboard and the WebRTC cast work - we can connect the system to pretty-much any HDMI signal and view it from anywhere on the net. (Glossing over some configuration and security details.)
The client is wondering if there is any hacker or IOT device maker interest in purchasing the board as a product. He's not in the board business and wouldn't otherwise make and sell the device, but if there's enough interest he could be persuaded to build a run of boards and sell them to the community, or a bulk sale to a device maker.
The board would cost roughly $70, and be essentially an HDMI->CSI bridge, with an HDMI "output" so that the device could connect between two HDMI devices.
Is that the sort of thing hobbyists would be interested in?
If there's enough interest, we could put the designs and software up as open source (hardware and software), then sell boards.
Let me know in the comments if you think this is something people would want.