These days we’re marinated in news all day long – meaning that Marion Stokes was way ahead of her time. For more than 30 years until her death in 2012, the Philadelphia resident recorded the news 24 hours a day. More than 70,000 tapes of footage were amassed, covering everything from the 1979 Iranian hostage crisis to the 1986 Challenger shuttle disaster, 9/11 and the Sandy Hook massacre.

Director Matt Wolf has spent the past five years sifting through Stokes’ 70,000 tapes and 50,000 books (not to mention a collection of Macintosh computers). He has pulled together a compelling narrative around her obsessions and the ways in which they affected her life and family. “This is an archive which has anything and everything,” Wolf says. “History takes on greater meaning as time passes and Marion was so invested in knowledge and truth – it’s just that she didn’t know what would have meaning or truth in the future, so she had to record it all.”

The result is a film called Recorder: the Marion Stokes Project – curated and spliced footage that veers between local news oddities, such as giant cookie bakes and children stuck in pipes, to events of global interest. It’s all intercut with video of the firebrand Stokes and interviews with her family. “Looking through the footage showed me so clearly how the media shapes our perceptions,” Wolf says, “and this was way before and so much more complex than ‘fake news’. There are a few events where television was at the centre of history-making: man walking on the moon, JFK’s assassination, the Challenger explosion. What’s so visceral is seeing how the media catches fire in real time to these world-changing events and then how we learned it all through television.”

Born in 1929 and adopted into a working-class family, Stokes became a committed communist; she wanted to relocate her first husband and young son Michael to Cuba in the 1960s. She failed to convince her family and so remained in the US, her activism and reputation for uncompromising debate leading to a late night spot on local television hosting a panel show on the political issues of the day with her soon-to-be second husband John Stokes. She was something of an eccentric local celebrity, only leaving the house to film her show and to have a daily martini at her local bar.

Facebook Twitter Pinterest Marion Stokes enjoying a martini in 2009. Photograph: Marion Stokes Estate

“She had been collecting books and newspapers for most of her life,” says her son, Michael Metelits, “but the television thing really took off from the 1979 Iranian hostage crisis. That was when she became obsessed with the way stories were reported and how they changed. I was 18 at the time and it struck me as strange, but my mother was strange for her whole life.”

Beginning with taping just one channel on the hostage situation, her preoccupation soon expanded into a 24-hour affair across multiple networks. “She would be stationed in the room with one or two TVs going and she’d be recording,” Metelits says. “There were times when tapes needed to be changed and that became a form of controlling the flow of conversation around her. If there was a difficult moment, there would be a pause where she said she needed to change the tape.”

Stokes insisted on recording on VHS, resisting going digital or purchasing recording services such as TiVo as she was worried her recordings might be accessed or tracked. The taping soon became an obstructive presence in Stokes’ life – seemingly not for John but for Michael and John’s children. “The bizarre arc of my mother’s life is compelling,” Metelits says, “but it was difficult to live in. It was inspiring that my mother had an encyclopaedic intellect but she would use it in an adversarial fashion and that never made it easy to talk to her. She would see connections between things that no one else would; but that could come at the cost of her emotional relationships.”

The film carefully skirts the issue around whether Stokes was an eccentric visionary – an archivist of a medium that has come to define our lives – or an obsessive hoarder. “I want the film to generate an emotional experience around ideas,” Wolf says. “I was very adamant that the film not resort to psychological explanations of why Marion does what she does. I didn’t want to pathologise her as a hoarder, since someone can be dysfunctional and insightful, those two things can coexist, and Marion is a very unexpected example of that.”

One of the most compelling uses of Stokes’ collection in the film is a four-screen grid of the events of 9/11 unfolding in real time. One by one, each screen breaks the story, a slow patchwork of shock and meaning combined to leave the viewer with the one, searing image of the plane crashing into the monolith. It is a visual collage which not only bears witness to a key historical event but also reflects the multiple perspectives from which people around the world would have viewed it from.

“She was very much ahead of her time,” Metelits says. “She wouldn’t be confused at all by the hall of mirrors we see in the news media and social media today. She believed that what she was doing was something of a tonic; a way to inoculate yourself from the chaos.”

• Recorder: The Marion Stokes Project is at BFI London film festival on 4 October