Uber has held recent talks to buy Seattle-based Mighty AI, a startup that helps autonomous vehicle developers train their computer vision algorithms to better identify objects on the road, said three people briefed on the discussions.

The potential deal is another sign of a looming shakeout in the self-driving car field, where companies have collectively raised billions of dollars to tackle similar problems. Companies in the business have extended the timelines for launching driverless cars en masse to the public as they realize the efforts will take longer than expected. That could mean less near-term business for vendors offering software to those developers, including the tools Mighty AI provides, known as data annotation.