ATMediaFile

ATMediaFile is not a content type that you install in your Plone site, but a base class used for ATVideo and any other product that wants to take advantage of the ATMediaFile's functionality.

Functionality

ATMediaFile subclasses from ATFile but overrides the FileField to use an external storage layer. Currently, we are using ExternalStorage as the storage layer, but there are branches of ATMediaFile that use other storage layers such as FileSystemStorage. https://svn.plone.org/svn/collective/ATMediaFile/branches/nate-filesystemstorage-branch/

The purpose of using ExternalStorage (or FileSystemStorage) is so that the file is stored on the file system instead of in the ZODB.

Bittorrent support

There is a branch of ATMediaFile that has implemented support for Bittorrent, which means that everytime you upload a file into Plone, the file is stored on the file system along with a .torrent file.