Video is hard, and reliable timestamps in increasingly virtual environments are even harder.

We at Mux recently broke ground on a new live video experience, one that takes a website URL as input and outputs a livestream. We call it Web Inputs. As with any abstraction, Web Inputs hides quite a bit of complexity, so it wasn’t long before we ran up against our first “unexpected behavior”: our audio and video streams were out of sync. This talk walks you through our experience triaging our timestamps troubles. It’s a narrative account that puts equal weight on the debugging process as the final implementation, and aims to leave the audience with new perspective on the triage process. I hope you’ll learn from our mistakes, a bit about Libav audio device decoders, and hopefully a new pattern for web-to-video streaming. This talk was presented at Demuxed ’22, a conference for video nerds in San Francisco featuring amazing talks like this one. Demuxed ’22 was made possible by sponsors like our Platinum sponsor Daily (https://daily.co) and organized by people from Mux (https://mux.com). For more information about the conference and community, see https://2022.demuxed.com.