yes it is possible... well to an extent. whenever you encode something differently a little bit of quality will be lost. but for he most part if you encode with the proper settings the data loss is to most unnoticable... if the file is an avi and you want the same quality... open quicktime and press command-i or go to window-> show movie inspector. looks at the specs in that window... plug those same specs into visual hubs encoding preferences and then encode... i am not 100% sure but that should work out for you.
