Brian Roberts, CEO of Comcast, is coming for Facebook and YouTube. Getty Images, Kevork Djansezian Comcast is preparing to launch a major new video platform with content from big-name partners in the coming weeks, Business Insider has learned.

The platform is currently called "Watchable," but there's a small chance that could change before launch.

The Information's Amir Efrati previously reported that Comcast was thinking of launching a digital video service, but here are more of the details.

Comcast is partnering with major digital publishers like Comcast-backed Vox and Buzzfeed, lifestyle, and comedy sites like AwesomenessTV, Refinery29, and The Onion, news sites like Mic and Vice, as well as legacy brands like NBC Sports to come up with a widespread digital-video platform that will rival YouTube and Facebook's online video efforts.

It will also rival the rumored video platform Verizon is preparing to unveil.

The full list of partnering media companies is still being determined, sources say, but participants are committing to Comcast for up to a few years. As part of the partnership, the publishers have agreed to upload all unlicensed, original video content to Watchable for users to stream on demand. The content from the publishers will be bundled and curated for Comcast's millions of Xfinity X1 box owners, and eventually Watchable will also be available on iOS and Android devices.

Comcast already has a smart-TV solution called Xfinity. The X1 set-top boxes allow users to stream unlimited amounts of movies and shows on demand from their televisions or mobile devices.

Over the next few years, sources say, Comcast plans to switch out all of its subscribers' boxes for X1 boxes, which could extend a platform like Watchable from just a few million households today to tens of millions of Comcast subscriber homes by 2017.

Comcast will be pushing all its cable customers to switch over to Xfinity boxes over the next few years, from which "Watchable" can be streamed. Flickr/mr_t_in_dc Comcast is hoping to establish itself as the digital-video advertising leader, sources familiar with Watchable say.

"Comcast is currently the largest seller of video ads in the United States," one says. "As platforms shift to digital, Comcast doesn't want to lose market share, but they're losing it to YouTube and Facebook."

Publishers get exposure; Comcast saves licensing fees

Publishers seem interested in Comcast's platform for two reasons.

It's a new marketing opportunity, allowing online-only brands to get in front of TV watchers. It's a potential big new revenue stream.

Watchable could help digital publishers make a critical leap from being online-only brands to household names among traditional television viewers. If digital-media companies can successfully cross that chasm, their brands will become much more valuable, and they'll be able to attract the massive advertising dollars cable networks have long enjoyed.

"Everybody is looking to see how digital companies are going to be able to produce video content that can move the needle in a meaningful way," one publisher told Business Insider.

If Watchable takes off, it could also become a significantly cheaper content model for Comcast as well. Currently, Comcast has to dole out cash on a per-subscriber basis to networks like ESPN and CNN. But Comcast won't pay any licensing revenue to Watchable partners, only advertising revenue.

Deals are nonexclusive, so publishers will still be able to post content natively to Facebook.

Comcast Watchable is just the latest solution to emerge in the ongoing video-platform wars. In the end there could be one big winner, or multiple. One source likened the current video environment to driving through a tunnel and being unsure what you're going to find on the other side.

"I think on any of these [Comcast or Facebook] platforms there will be a hybrid of traditional TV content and then the digital players. It will be really interesting to see how things shake out over the next 18 months."

Comcast declined to comment for this story.