I must say that, following all the male roles taken by women in, eg, modern interpretations of Shakespeare (will a man ever again be permitted to portray King Lear?), it makes a nice change to see a man take a female role, as François Ozon adapts Rainer Werner Fassbinder's play/film/opera for a male lead. Denis Ménochet gives a good portrayal of the mercurial, self-indulgent film-maker in what turns out to be an at times uneven production.
A constant presence in the background is Karl, von Kant's assistant. Played by Stéfan Crépon, he has no lines but instead conveys his emotions by facial expression. This would be a difficult task for any actor, and at times Crépon over-does the eye acting as Karl gazes, hurt, at von Kant, following yet another example of his employer's disregard of his feelings. The other male character is Amir, object of von Kant's affections. In this role Khalil Gharbia provides the weakest performance of the film, at times too obviously acting even in such a mannered production as this.
The film was worth seeing once, but I doubt I will bother watching it again.