Joplin died of a drug overdose in 1970. She was 27.
"This is my next project for sure," Daniels told the entertainment industry trade newspaper about making a movie about Joplin's life story. "I had no idea Janis Joplin was so smart -- intellectual, even. Look, some of the smartest people in the world have been drug addicts."
Daniels said he thinks Adams -- whose films include "Junebug," "Enchanted," "The Fighter" and "The Master" -- will be perfect to play the doomed musician.
"Guess what? She can sing her ass off!" Daniels said of Adams. "After Joplin, I'm hoping to get 'Miss Saigon' off the ground. And then -- I want to make a horror movie!"
Daniels has earned rave reviews for his drama "The Butler." His other films include "The Paperboy," "Precious" and "Shadowboxer."