In a lot of cases, the Picture [Film] has been adapted, from a Book or stage play, by the Screen writer. Who in most cases, is not the original author. So check on the cover of the video, DVD or with the studio credits, to filch out the details.

Which ever way it goes, permission has to be gained to perform or adapt prior to performance. Unless it is out of copyright & in the public domain. I think this happens automatically, 70 years after the authors death in your country, where here it is only 35 years!

I hope this may help!

Chookas Donna