Once again the Internet has failed me. I was using the Pitivi non-linear video editor, and discovered my three minute video had the end of the timeline (where the video ends) at over ten minutes. This would triple the render time: unacceptable, time is money.

You can reach the start/end of the timeline by pressing the Go To Start and Go To End buttons on the video player thing. I spent quite some time trying to find how to alter the timeline end.

Turns out there’s no way to move or adjust the end of the timeline. However if you close the project and reopen it, Pitivi correctly detects where the last clip ends and makes that the end of the video. Render time reduced.