Here is an article from The Daily Mail......This is all the information we have at the moment.
RACHEL GRIFFITHS, whose searing performance as Jacqueline du Pre's sister Hilary in the film Hilary And Jackie won her a Best Supporting Actress Oscar nomination. She will star with Jonathan Pryce and Ioan Gruffudd and Matthew Rhys as characters called Hob and Nob - don't ask! - in a new comedy drama, Pavarotti In Dad's Room, set in South Wales. Writer-director Sara Sugarman's story is about a former Eisteddfod singing competition winner who lives with her father, a baker called the Voice of the Valley because he sings through loudspeakers on his delivery rounds. Mr Pryce, an award-winner on both sides of the Atlantic for his role in the musical Miss Saigon, has been having singing lessons.