'Harry Potter' actor slams his performance: 'I think my work is mediocre'

Gary Oldman is taking issue with his work in the "Harry Potter" film franchise.

Oldman, who played the role of Sirius Black in four of the series' eight movies, was discussing his experiences filming the beloved series in a new interview when he admitted, "I think my work is mediocre in it."

Josh Horowitz spoke with the actor for the "Happy Sad Confused" podcast, and when he admonished him for the critique, Oldman doubled down.

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Gary Oldman portrayed the role of Sirius Black, godfather to Harry Potter, played by Daniel Radcliffe. (Warner Bros./courtesy Everett Collection)

"No, I do," he said. "Maybe if I had read the books like Alan . . . if I'd got ahead of the curve a bit, I would have played . . . if I'd have known what's coming, I honestly think I would have played it differently."

Earlier in the interview, the subject of fellow "Harry Potter" star Alan Rickman came up. Rickman, who played the role of Professor Severus Snape in all eight movies, was famously the only actor who had been informed early on of his character's fate by author J.K. Rowling.

Gary Oldman believes his performance in the "Harry Potter" films could have been better. (Dominik Bindl/Getty Images)

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Oldman's performance in this franchise isn't the only one he dislikes.

"Tons of it," he said of his work in past movies. "I'd put it all on a fire and burn it and do it all again." For example, when asked about his work in "Bram Stoker's Dracula," he said he's "not crazy about it."

Gary Oldman isn't a fan of many of his past performances. (Gabriel Olsen/Getty Images for AARP)

He continued, "It's like anything. If I sat and watched myself in something and said, ‘My god, I’m amazing,' right, that would be a very sad day, because you want to make the next thing better . . . and it's so subjective. It's such a personal thing that you're looking at that other people are not seeing. It's not to disrespect someone who says to me, ‘Oh, I really loved you in that movie’ and I'm thinking, ‘I’m terrible in that movie, what are they talking about?' It's not that. They're seeing something else."

He said that he believes that that level of "nitpicking" one's own work can be "healthy," but "you can't let it debilitate you." Oldman confirmed that while he can be critical of himself, he doesn't beat himself up over past acting choices.

Gary Oldman said the hardest thing he's ever filmed in his career was a scene for his first "Harry Potter" movie. (Kate Green/Getty Images)

At another point during the conversation, Oldman talked about how one moment in the filming of "Harry Potter and the Prisoner of Azkaban," his first film in the series, was "the most difficult thing" he's ever done in his career.

"I had to lie by the lake, there was like this frozen lake, and I'm sort of dead, and the soul is leaving my body," he remembered.

Daniel Radcliffe (Harry Potter); Gary Oldman (Sirius Black); Emma Watson (Hermione Granger) ; Michael Gambon (Dumbledore) and Rupert Grint (Ron Weasley), pose at a photocall at London's Liberal Club in 2004. (MARTYN HAYHOW/AFP via Getty Images)

"It was just me laying down, but ‘Harry Potter,’ they would shoot . . . it took forever," he said. "It was slow. You'd be on a scene for a week, we normally could shoot this in two days. But anyway, I was on that . . . what they did was build this lake inside this studio and they cooled it down and they froze this lake, and I had to just lie there for a week, day in, day out, doing nothing."

He recalled complaining that he was getting cold, and said a crew member placed a hot water bottle under him, and a couple of days later he received a pillow to put under his neck after complaining about pain there. He laughed, "The hardest thing I had to do was lie next to a frozen lake."

Emily Trainham is an entertainment editor for Fox News Digital.