TORONTO -- Shock rocker Alice Cooper, "Star Trek" favourite George Takei and the puppeteer behind Big Bird and Oscar the Grouch are among the personalities expected at this year's Hot Docs film festival.

Organizers said Tuesday that the annual documentary marathon will kick off April 24 with Brian Knappenberger's "The Internet's Own Boy: The Story of Aaron Swartz" while special presentations include Cynthia Hill's domestic abuse study "Private Violence" and Jesse Moss's "The Overnighters," about a pastor who helps desperate men looking for work in a small North Dakota community.

Cooper will be on hand to premiere the so-called "doc opera" "Super Duper Alice Cooper" and take questions alongside directors Reginald Harkema, Scot McFadyen and Sam Dunn. Cineplex Entertainment will simulcast the event to 47 theatres across the country.

Takei and puppeteer Caroll Spinney will meet audiences as part of the Scotiabank Big Ideas Series. Takei will discuss his roles as actor, activist and social media master in "To Be Takei;" while Spinney will discuss "I Am Big Bird: The Caroll Spinney Story." At age 80, he is the last of the original "Sesame Street" puppeteers.

Meanwhile, oceanographer Dr. Sylvia Earle will be on hand to support her maritime expose "Mission Blue," which comes from the producer of "The Cove."

Hot Docs executive director Brett Hendrie said the lineup features more speakers at the various screenings -- whether they are journalists, artists, film subjects or activists plugged into the issue being featured.

"We're really focused less on celebrities per se and bringing in subjects who can speak after the film and get conversation and dialogue sparked about some of the things that are going on in the film," Hendrie said following a press conference attended by several filmmakers.

He touted Knappenberger's opening night film as a personal favourite, as well as "I Am Big Bird: The Caroll Spinney Story" because of a special connection it has to the Toronto doc showcase.

"The filmmakers used to be Hot Docs volunteers, so it's the circle of life," he quipped, adding that he expected Spinney to bring Oscar the Grouch with him to the festival.

This year's program features 197 documentaries from 43 countries.

The Canadian spectrum includes Thomas Wallner's look at six aging Belgian transvestites and transsexual performers in "Before the Last Curtain Falls," Tony Girardin's story of a bicycle craftsman attempting a world cycling record at age 75 in "Marinoni"; John Kastner's return to the Brockville Mental Health Centre in "Out of Mind, Out of Sight" and Amar Wala's story of five Muslim men imprisoned without charge in "The Secret Trial 5."

Wala, a first-time feature filmmaker, said he hoped the world premiere of his film will spark real change.

"Is a person being held in jail for seven or eight years without being charged with a crime OK in this country? I don't think it is and I think that most Canadians will agree with me," said the 31-year-old Wala, who described his Hot Docs debut as "a surreal experience."

"I'm hoping that a public voice will help sort of resolve this issue once and for all."

The international slate includes Robert Greene's portrait of "The Wire"'s Brandy Burre in "Actress," Helen Simon's family saga "No Lullaby," while the world showcase program includes Ryuji Otsuka's "The Beijing Ants," about capitalism and customer service in modern China, and Ryan Murdock's "Bronx Obama," about a Barack Obama doppelganger.

Previously announced films include the Canuck feature "The Sheik," about Khosrow Vaziri's transformation from Olympic wrestler to pop culture icon; the Russian film "Children 404" about LGBT youth, and the U.K. offering "A Dangerous Game," which looks at everyday heroes battling the Donald Trump empire.

Programming director Charlotte Cook touted live events including "The Measure of All Things Live Documentary" on April 26. Director Sam Green will narrate live while musicians The Quavers supply a live soundtrack to this film, inspired by the Guinness World Records book series.

The special Q&A screening of "Super Duper Alice Cooper" -- a film that blends archive footage, animation and interviews with Elton John, Iggy Pop and John Lydon -- is set for April 28.

The film's co-director Dunn said it's a stylistic departure from rock-docs he's done in the past.

"There's no talking-head interviews in this film. Visually it's all told using archival footage, archival photographs, home movies, music videos, live performance and the rest of it," said Dunn, whose past projects include "Metal: A Headbanger's Journey," "Iron Maiden: Flight 666" and "Rush: Beyond the Lighted Stage."

He added that Cooper was long overdue for a feature documentary.

"There are these legends of the '70s that have never really had their proper due in terms of documentary film. We found that with Rush, we found that with (Iron) Maiden and Alice Cooper just falls into that category," he said.

"I think the average person on the street doesn't realize that Alice Cooper is still touring and still filling arenas in good-sized venues."

Hot Docs expects to welcome more than 2,000 industry delegates to industry events including conferences, parties and pitch programs.

The Hot Docs Canadian International Documentary Festival -- billed as North America's largest documentary festival, conference and market -- runs April 24 to May 4.