2 Questions: 1) Once a file has been optimized (moov atom placed at the beginning), is it necessary to re-optimize a file after editing the metadata? 2) I have about 300 m4v movies. Some have been optimized (either using Subler or Handbrake), but not all (older rips). Is there a way, on a Mac, to tell where the mood atom is located? Just don't want to be taking time to re-optimize if it's not needed.