I love these sort of challenges but I guess the answer from noggin is the way to get these HD recordings from a freeview transmission stream, I imagine with some research it's possible with Sky as well.
For domestic use - yes - recording the streams yourself outside of the Freeview/Freesat licensed ecosystem is the easiest solution.
However in a broadcast environment, it's much easier to arrange to disable HDCP en route to an HDMI to HD-SDI conversion... (Which also allows easy recording of encrypted Sky and Virgin Media content)
And yes - Hollywood studios hate this. And yes - Hollywood studios are also major customers for Blu-ray players with HD-SDI outputs that use HDCP disabling HDMI to HD-SDI converters - as many high-end cinema projectors don't have HDCP and are fed HD-SDI...