Mary Poppins actor Dick Van Dyke has taken a starring role in Coldplay's latest music video, as he prepares to celebrate his 99th birthday.

Filmed in his beachside home in Malibu, the moving video sees the star reminisce about his life and reflect on old age.

"I'm acutely aware that I could go any day now," he says, "but I don't know why it doesn't concern me. I'm not afraid of it. I have the feeling that I'm gonna be alright."

Set to the ballad All My Love, the video was co-directed by Mary Wigmore and Oscar-winning filmmaker Spike Jonze, whose movies include Being John Malkovich, Her and Adaptation.

Running for seven minutes, it's a touching and intimate portrait of the beloved actor, whose other credits include Chitty Chitty Bang Bang, Bye Bye Birdie and the TV show Diagnosis: Murder.

He allows the filmmakers to tour his home, showcasing memorabilia from his movies - including a lifesize replica of Bert, his chimney-sweeping character from Mary Poppins.

The star also recreates The Twizzle (an impossibly flexible routine from his 1960s TV sitcom, The Dick Van Dyke Show) as Chris Martin serenades him on the patio of his house; and dances barefoot with his wife, Arlene Silver.

But the most emotional moment comes as he talks about his four children, Christian, Barry, Stacy and Carrie Beth.

Van Dyke gazes lovingly at a photo of Stacy being read a bedtime story, and reveals: "I've had dreams where I'm depressed or lonely or hurt, and she comes to comfort me. She actually comes to comfort me."

His family - including dozens of grandchildren - arrive later in the video, dancing and singing with the actor, who tells Martin he is particularly taken with one line of All My Love: "Until I die / Let me hold you if you cry."

The video ends with Martin improvising a song for the star, who watches in astonishment as the music comes to life.

"Have we got that on film?" he asks. "Can you believe this man?"

All My Love is the latest single from Coldplay's 10th studio album, Moon Music, which went to number one in October.

The group have taken a quirky approach to promoting the record, hosting a segment on the shopping channel QVC, and filming an impromptu video for the song We Pray in the middle of Dublin's Grafton Street, shortly before they played a show at the city's Croke Park Stadium.

An earlier video for All My Love also saw Chris Martin walking the streets of Las Vegas in disguise, singing karaoke and handing out balloons to strangers... a scene which Van Dyke briefly recreates in the latest clip.

The video premieres on the band's YouTube channel at 13:30GMT on Friday, 18 December. A shorter edit will be released on 13 December, to mark Van Dyke’s birthday.