(CNN) -- Last summer, a call for submissions went out through YouTube to get user-generated video footage of what people all around the world did from midnight to midnight on July 24, 2010.
One year later, that footage has been viewed, tagged, rated, cut, edited and set to music for the release of director Kevin Macdonald's documentary "Life in a Day."
Made up of many small, emotional moments like a boy shaving for the first time, an older couple listing dirty acts in their wedding vows, a family coping with the wife's mastectomy, a sky diver's exhilarating descent, a man on his deathbed and a disturbing sequence of animal slaughter, "Life in a Day" is a time capsule of planet Earth.
The project originated when YouTube approached Ridley Scott's production company about creating a film to celebrate the Internet video giant's fifth anniversary.
When Macdonald ("The Last King of Scotland," "State of Play") was approached for ideas, he immediately looked to the work of obscure documentary filmmaker Humphrey Jennings.
Jennings' most famous film, "Listen to Britain," was made during World War II.
"It's very poetic," Macdonald said, "where you don't have any dialogue; you just hear and see the sights and sounds of Britain with little snatches of music and little bits of dialogue in the distance, the wind in the corn (fields), planes overhead, bombs going off. It's trying to evoke in 25 minutes what this country is like at one point in time."
In addition to the request for documentary video footage, Macdonald posed three questions to be answered on video: What do you fear? What do you love? What's in your pockets right now? This component was another nod to Jennings' work, this time from his 1937 Mass Observation project.
"It sounds like something out of George Orwell's '1984,' " Macdonald said. "(Jennings) asked people to write diaries of their lives. Ordinary people around the country, about 500 people at a time, would write down the most detailed things: 'I went to the butcher and got two pounds of liver. The butcher said to me, "blah blah blah." '
"Then they'd ask questions," he continued. " 'What is on your mantelpiece' is a favorite of mine, and 'what is the name of five dogs you've seen today?' They did diaries, and I thought we could do that with video. It was that simple. We stole (the idea) from somebody else. It's always the best way."
With 81,000 submissions from 192 countries totaling 4,500 hours of video, Macdonald and the film's skillful editor, Joe Walker, recruited 25 assistant editors to watch 12 hours of video a day for 2½ months.
In that time, they rated the footage from one to five. "One was truly awful," Macdonald said. "The joke was if you got a one, you put less effort into filming it than we did into viewing it. Five was, This is fantastic. And then there was a six for so bad, it's good. But that was just for our personal amusement."
After the team found 10 hours of the best clips and characters, it was up to Macdonald to make sense of the footage.
"I wanted to make a movie," he said. "Not just best-of clips."
While combing through the footage, he found common themes: How people relate to family, love, work and food (look for the watermelon-only short film on the DVD extras).
Almost everyone who entered a video took the project seriously and followed the rules, but Macdonald did discover some clips that were not filmed on July 24, 2010, and other unusable footage like a man's dubiously memorable scatological submission.
"Disappointingly, there were not a lot of sex submissions." Macdonald joked. "Though, I'm told that YouTube gets a lot of ... male masturbation shots, so I'm kind of glad I didn't get any of that."
There were other instances in which Macdonald loved a particular clip but couldn't fit it into the film's emerging structure. For example, a naked Korean man pouring milk on himself and playing an organ in a tree. "We named that clip the Naked Korean Milk-Spilling Organist," Macdonald said with a laugh, "which is the title for my first novel probably."
Macdonald says he made "Life in a Day" as a "sort of a reaction to the studio movies that are somewhat deadening artistically. I had complete and utter artistic freedom for the first time in my life. There was no one saying 'you can't do this' or 'you must have that' or 'we don't want a cow being slaughtered.' "
Which brings us to the unnerving scene of a terrified cow getting shot in the head.
"It was important to put into the film things that are the darker side of life," Macdonald said. "I don't want this to feel like a Coca-Cola commercial. That would be very boring. You have to show the reality of life; otherwise, it's not a true representation. There is death, there is tragedy, and a lot of animals die every day for us to eat.
"The clip is so striking," he continued, "because it's done in such a matter-of-fact way. And yet the animal is looking at the camera, and you can see that it knows what's happening. It's tragic, weirdly beautiful and horrific. I thought, if I left that out, I'm censoring something I know is really powerful and something that I know goes on all the time. I'm not a vegetarian, but I sort of suspect I should be a vegetarian, and that makes me want to be a vegetarian even more. Isn't it right that we actually see what it is that we're doing?"
Since "Life in a Day" wrapped, Macdonald and his fellow filmmakers (who are credited as co-directors) have stayed in touch and, in some cases, toured the press and festival circuit together. Now with the film ready for theatrical release, this ongoing sense of community will organically extend to viewers as well.
"The fact that it's amateur in the best sense of the word, meaning that people have done it for love and not money, gives the film a different quality," Macdonald said. "It's part of the community aspect. These people are sharing themselves in the best tradition of the Internet."
Life in a Day opens in select theaters on July 29.