It's impossible to instantiate VideoFrame outside of gstreamer-video crate

Use case:

I would like to use VideoFrame to map a buffer but with extra mapping flags, for example GST_MAP_GL.

My first approach is to add an external trait which will be implemented for VideoFrame, but it's impossible to implement it outside of gstreamer-video crate since VideoFrame structure constructor is private, and it is private because it's build with ffi objects.