1.	So that's the philosophy, now let's put some meat on the bones.
2.	RSS already does most of what we want. With the addition of the <enclosure> sub-element of <item> any RSS element can describe a video or audio file (actually any type of file).
3.	<enclosure> has three attributes: url says where the file is located, length says how big it is, and type says what its type is. This way a workstation or aggregator can know in advance, without having to do any communication, what it's going to get, and apply scheduling and filtering rules.