You don't even need go get the chips, devices like this strip the HDCP and turn the stream into MJPEG.
http://blog.danman.eu/reverse-engineering-lenkeng-hdmi-over-...
Here is their 4K device, don't know if it works like the HD device, but it would seem there is a fair chance it does.
http://www.lenkeng.net/Index/detail/id/147
You can buy these devices on eBay.