Subler, mp4 remuxer/editor
Subler is an incredibly useful Mac app to manage media files which contain h.264 video and various audio formats. In one sense, Subler is a remuxer: it lets you take the underlying content and put it into whichever format you need, without converting the content like Handbrake would.
What’s really nifty is that it’s also an editor. Subler hooks into thetvdb.com and themoviedb.org to add the relevant metadata (name, episode number, season, summary, etc.) into the file in a format which iTunes can understand. You can add the ‘HD’ tags which iTunes uses, control artwork, and manually edit all of the metadata contained in a file.
It’s GPLv2 (free!), and uses Perian to do some of the heavy lifting. It also has a useful CLI version which can allow you to automate some of its featureset.
