Veronika Voss (1982)

Directed by Rainer Werner Fassbinder

In Munich 1955, German film star Veronika Voss becomes a drug addict at the mercy of corrupt Dr. Marianne Katz, who keeps her supplied with morphine. After meeting sports writer Robert Krohn, Veronika begins to dream of a return to stardom. As the couple's relationship escalates in intensity, Veronika begins seriously planning her return to the screen -- only to realize how debilitated she has become through her drug habit.

This is basically Sunset Straße by 'Wilhelm Wilder', right? I mean, apart from the obvious allusions in the plot, there are Billy Wilder references in the director's hat, and, I think, in that Robert Krohn is a reporter in Berlin — just like Wilder himself.