Screenwriter John Ridley immersed himself in the 1800s for “12 Years a Slave” and dove into the 1960s rock scene for Jimi Hendrix biopic “All Is by My Side” (pictured above), both playing in Toronto.Meanwhile, he’s ready to focus on 1992 Los Angeles as he tries to get his “L.A. Riots” script off the ground with Imagine Entertainment.Both Toronto films were in production during the late spring last year, with Ridley directing “All Is by My Side” in Dublin and consulting on the script while shooting on Steve McQueen’s brutal epic “12 Years” took place in New Orleans. “That was a little tricky,” Ridley recalls.

A fan of Hendrix since high school, Ridley years later discovered the Hendrix song “Sending My Love to Linda,” about fashion model Linda Keith, who heard Hendrix perform in London in 1966 and played a key role in encouraging his career.

Ridley, whose writing credits include “Red Tails” and “Three Kings,” did a 2010 show about “Sending My Love to Linda” for National Public Radio and then decided to do the feature independently.

“I knew it would not be a studio script,” he notes. “If Paul Greengrass and the Hughes Brothers are having problems, then it’s not going to happen for me.”

Outkast’s Andre Benjamin, who stars as Hendrix, learned to play like the maestro — left handed with a right-hand guitar strung upside down — to boost the authenticity of the film. Ridley looked to model the Hendrix pic on singular biopics like “Sid and Nancy,” Lenny” and “Coal Miner’s Daughter” — films that tell stories that transcend the artifice of the performance.

Ridley’s also been working on rewrites of his “L.A. Riots” script with Justin Lin attached to direct. He’s hopeful that “12 Years” and “All Is by My Side” can generate enough success to push “Riots” toward production.

“It was a Black List script that I wrote on spec and sold in 2007 before the world changed financially,” Ridley notes. “I feel like we’ve got to make this happen now. People often think that it was limited to Rodney King and Reginald Denny, but there are so many other interconnected stories.”

Two decades after the fact, Ridley remains amazed that Los Angeles Mayor Tom Bradley and LAPD chief Darryl Gates had not talked for a year prior to the April 1992 riots, which left 45 people dead.

“It was a systemic meltdown,” Ridley notes. “The city and how it functions is the primary character of the film.”