One of the good parts of doing it at the leaf hashes over the top level hash as proposed further up the thread is that quicktime/avi/etc are much more amenable

One of the good parts of doing it at the leaf hashes over the top level hash as proposed further up the thread is that quicktime/avi/etc are much more amenable to carrying some "junk" data than trying to figure out two colliding merkle tries with the same hash.