Comcast has acquired Watchwith, a startup that has built a “deep metadata” video platform that tracks info down to the scene level.

Terms of the deal, which closed last month, were not disclosed. San Francisco-based Watchwith had raised about $15 million from investors including Rogers Venture Partners, Samsung, Arris Group and Gracenote (which itself is being acquired by Nielsen).

“We built Watchwith so TV programmers and (multichannel video programming distributors) could rapidly innovate new video features and user experiences,” Zane Vella, Watchwith CEO and founder, in a statement. “We’re thrilled to now help bring those experiences to the X1 and other Comcast platforms.”

Watchwith is now part of the Comcast Metadata Products and Search Services (CoMPASS) team, which develops and maintains the platform that powers the cable company’s video applications with video metadata and content-discovery services. CoMPASS has also been a key part of Comcast’s X1 architecture to support syndication to partners such as Cox Communications and Shaw Communications; the operator recently struck a licensing deal for X1 with Canada’s Rogers Communications.

Vella has joined Comcast as VP of product, along with Watchwith’s 15-person team. Vella founded the company in 2006 as Related Content Database Inc. (RCDb), and it changed its name to Watchwith in 2012. Comcast already has worked with Watchwith, using its system to launch a sports highlights app on X1 last year.

According to Vella, Watchwith will continue to serve TV programmer customers with the Comcast acquisition, in the same way Comcast’s FreeWheel and ThePlatform divisions have worked with outside clients following their acquisition by the cable company. Watchwith customers have included NBC, Bravo, USA, Syfy, Fox, CBS, Disney, Viacom and Turner.

Watchwith’s system lets producers and editors manually tag their video to provide metadata about individual scenes, and it also provides media-analysis technology to automatically tag videos using computer vision and machine learning.

Separately, last fall Watchwith’s former chief experience officer, Geoff Katz, joined Fox Networks Group as senior VP of advertising product management, where he heads non-linear ad product strategy and execution.