This is a fascinating documentary on the making of Klassenverhältnisse (Class Relations). Farocki is both an actor and a director of this documentary. The film focuses on the rehearsal of two scenes (the "missing photo...展开in the bag" scene and the "I'm completely drunk and I'm going to ruin your life" scene) and the shooting of the first rehearsed scene.
Like Pedro Costa's beautiful film on Straub & Huillet, Farocki's take focuses on the meticulous, obsessive work of the authors while at the same time incorporating a cinematic pace akin to their films'.
Here we see not the final step (editing) but the very early phases of the construction of the film. While working with the actors, while making them repeat the same scene over and over, Straub & Huillet are actually beginning to envision the mise-en-scène. We thus have the rare opportunity to see two master film-makers as they start to make actual progress in the artistic concretization of the work.
It may help if you have seen Klassenverhältnisse before, but it's really not necessary in order to follow this fascinating film.