Tilda Swinton reunites with Spain’s formidable auteur Pedro Almodóvar for the deeply dramatic look at friendship and mortality that is “The Room Next Door.”

Notable as Almodóvar ’s first English-language feature, “Room” won the Venice Film Festival’s top prize, the Gold Lion, at its world premiere last September and is hoping for Oscar gold when nominations are announced Jan. 17.

“Room” begins when Swinton’s Martha, terminally ill, reaches out to an old friend she hasn’t seen in years, Julianne Moore’s Ingrid.

Martha has made the choice to end her life. She’s bought a euthanasia pill on the black market and asks that Ingrid be nearby – in, exactly as the title says, the room next door – when the end arrives.

“For me this is incredibly personal. I’ve made no secret that I’ve had the privilege to be in the Ingrid position quite a lot,” Swinton, 64, revealed in a Zoom press conference from Tokyo.

“I’ve accompanied several Marthas on their way. This meant I could put my own experience in the film, the opportunity to step in shoes I’ve been sitting beside.

“My first Martha was my friend Derek Jarman” – the avant garde English filmmaker (“Caravaggio,” “War Requiem,” “Edward II”) and gay AIDS activist. Swinton starred in several of his films.

“He knew he wasn’t going to be living very long; he died in 1994. I learned from him an attitude of totally self-determination for the last three years of his life. I was able to take that as Martha’s attitude which is very familiar to me.

“Pedro gave me the opportunity to play someone close to myself. It was,” she said, “a little adventure through the forest.

“And when I first read it, I realized Pedro was talking about momentous things. Possibly the most momentous thing of all: How do we approach the end of life?

“This film,” she emphasized, “is all about living.”

Jarman and Almodóvar, now 75, are prominent queer directors which, Swinton noted, has often been the case.

“I’ve worked with many queer filmmakers over the last 30 years. When Derek and I in England discovered Pedro he was like a cousin. I would say we were admiring and maybe a little envious because we were in the (London filmmaking) underground but Pedro was front and center, right in the heart of Spanish culture.

“I think of Pedro as a master — and a master for so long. Most filmmakers in history, they have a glory period of maybe 8 years and then minor works. Pedro has been going strong for 40 years and 23 pictures.

“Now, in another language! It’s quite astonishing.”

“The Room Next Door” opens Friday