CUPERTINO, Calif. — Apple unveiled a new video streaming service on Monday with a parade of celebrities rarely seen on a stage outside of Hollywood’s awards season, with heavyweight directors like Steven Spielberg and J. J. Abrams and stars like Octavia Spencer and Jennifer Aniston.

Oprah Winfrey even served as the closer for the nearly two-hour event at the Steve Jobs Theater on Apple’s campus. “They’re in a billion pockets, y’all,” Ms. Winfrey said of Apple’s global reach. “A billion pockets.”

As enthusiastic as the entertainment industry appears to be to work with Apple, it is increasingly clear that Apple needs Hollywood. After years of record profits, the company is slowing down. Phone sales are cooling, and despite the relative popularity of products like the Apple Watch, the next big thing has eluded the Silicon Valley giant.

Now, short of another game-changing gadget and facing tough competition from rivals like Amazon and Netflix, Apple is trying to make sure you never leave all those Apple devices you have acquired over the years. The company unveiled an expansive strategy to push consumers to do more than just buy its hardware products. It has plans for new monthly subscription services for TV programming, video games and news, as well as a new credit card.