http://bugs.winehq.org/show_bug.cgi?id=20585
--- Comment #1 from Vincent Povirk madewokherd@gmail.com 2009-11-05 11:12:14 --- This would probably not be difficult, even in the general case. We could create a dummy decoder object that returns a picture of some text that says X file decoding is not available.
However, I'm not convinced it's better than simply reporting a failure to the application.