When the input is first selected here's will be a hot plug detect, EDID request and an EDID response. That response can be up to 32kB so anywhere up to ~2 secon

When the input is first selected here's will be a hot plug detect, EDID request and an EDID response. That response can be up to 32kB so anywhere up to ~2 seconds depending on how many extension blocks are in use by the display. Here's a nice breakdown on more of what happens there: https://research.nccgroup.com/wp-content/uploads/2020/07/hdmi_-_hacking_displays_made_interesting.pdf https://research.nccgroup.com/wp-content/uploads/2020/07/hdm.... When a suitable set of image parameters have been agreed HDCP (may) then step in to ruin your day. Again a nice walkthrough of that is available here: https://blog.cryptographyengineering.com/2012/08/27/reposted-cryptanalysis-of-hdcp-v2/ https://blog.cryptographyengineering.com/2012/08/27/reposted.... As other commenters have correctly noted, there's definite room for improvement. One thing to remember though is this involves hardware that can be in operation for the order of decades so there's a lot of cruft that accretes in order to maintain compatibility. Frankly it's mildly impressive that for the most part all the above happens in silence and continues to (mostly) work.