DVI is almost literally digitized VGA, with analog signals replaced by differential signalling and symbol encoding to keep it DC-balanced. HDMI extends it by en

DVI is almost literally digitized VGA, with analog signals replaced by differential signalling and symbol encoding to keep it DC-balanced. HDMI extends it by encoding audio and extra metadata (eg. used colorspace) inside blanking intervals (yes, they still use blanking intervals that were originally required for CRT displays). It doesn't do any handshake. Main difficulty is just high clocks required, and necessity to dynamically pick symbols (unless you only use few preselected DC-balanced values). DisplayPort and HDMI 2.1 are different, with packet-based transmission.