In a perfect world, all videos would have transcripts, and live videos would have captioning. It’s not just a requirement for people without hearing to be able to participate in pop culture and video chats, it’s a luxury for people with hearing who just prefer to read what’s been said. Not all software has captioning built-in though, and some that does relies on third-party cloud services to function. Live Captions is an application for the Linux desktop that provides instant, local, and open source captioning for video.

Source: Open source video captioning on Linux | Opensource.com