YouTube film 'Life in a Day' coming to theaters

One year ago, famous filmmakers asked YouTube viewers to upload a video reflecting a day in their lives. According to the filmmakers, people from all over the world uploaded a cumulative 80,000 videos, with 4,500 hours of footage.

The result of their edited efforts is the 90-minute documentary "Life in a Day." It's been described as "a historic cinematic experiment to create a documentary film about a single day on Earth."

Presented by YouTube and National Geographic, the film was made by a mighty duo of producer Ridley Scott and director Kevin Macdonald.

The trailer reveals stirring snippets of people talking about love and fear. In a National Geographic discussion with the filmmakers, Macdonald talked about the challenge of creating a narrative for the documentary. He asked contributors to tell their stories, talk about fears, and show what was in their pockets. "It offered us wonderful 'time capsule' material," editor Joe Walker said.

Footage that didn't make the cut will be posted on the project's YouTube channel.

Early reviews are good, though mixed. The Guardian described it as "enjoyable, as upbeat and happy as a pop video." Variety says, "[Audiences] willing to lose themselves in a kind of Internet-style armchair adventure will doubtless be swept up, though more critical eyes will note that the Western world is considerably on greater view in this assemblage than contributions from Latin America, Asia, and Africa."

Ridley Scott is best known for directing films like "Alien," "Blade Runner," and "Gladiator." Kevin MacDonald, best known for directing "The Last King of Scotland," and has won an Academy Award for the documentary "One Day in September."

The film premieres on Friday, July 29, in select theaters.

This story originally appeared on CBSNews.com's Tech Talk as "YouTube film 'Life in a Day' coming to theaters."