[amelius]

Yes, but the amount of encodings is pretty limited. It's better (imho) to make the encodings free of any viewer or browser. That way, we can more easily handle a large variety of encodings, and different versions of encodings. Anyone could make a new encoder, and create files using them.

You can see it as a "democratization" of encodings.

[janwas]

The FourCC at the beginning is indeed your encoding-id. This is common in file formats (e.g. RIFF). Out of curiosity, how is the 32-bit space insufficient?