> Since there is now an official specification, are there any
> plans to support extended XMP in exiv2?

Yes, we should do that as well as upgrade to the new version of the
XMP Toolkit. I've opened 2 issues but I won't have time to look into
this immediately.

http://dev.exiv2.org/issues/show/599
http://dev.exiv2.org/issues/show/600

Gilles,

Have a look at the document referenced by Marco, it contains useful
information about XMP and other metadata in video file formats.

Andreas