opposite of parse

[Josh Doe]

Silly question: what's the opposite of parse? I'm working with a
proprietary video container that only stores uncompressed frames
(simple header, minimal footers). I've written *parse (using
GstBaseParse), but now I need to be able to write to this format. *enc
doesn't make sense, since there's no encoding, and likewise with *mux
since there's no multiplexing (only video frames stored, no audio).
Thanks,
-Josh