I have a bunch of pretty big video files ... and I thought I w/could save a fair bit of space by tar-ing and zip-ping them. So

tar cvzf movie.tar.gz 1stmovie.m4v
To my astonishment the .qz file is the same size (1.9 Gig) - well a few Mb less - as the original file.

Is this "normal"? Or have I perhaps missed something?