This is a task usually done with HDMI capture cards, either PCI or even more expensive USB 3.0 HDMI capture boxes ... Once everything was figured out, [danman] was able to recover raw frames ...
XDA Developers on MSN2mon
5 cool uses for USB capture cards
Just keep in mind that most cameras with HDMI-out use the micro HDMI standard ... you have the option to connect a USB ...
"hsdaoh-rp2350" firmware enables high-speed data acquisition with Raspberry Pi Pico 2's HSTX interface and HDMI USB 3.2 video capture dongle ...