Which Arduino to buy to use with HD video

No, not at all.
Think baseband.

Mmmmmm are we talking about the same thing? I found this spec for HD video it shows mpeg2 as the compression method.http://www.hdv-info.org/HDVSpecifications.pdf

Mark

EDIT - Found two competing systems HDV and AVCHD the spec for which is here http://www.avchd-info.org/format/index.html

M