LosslessCut is a magnificent tool.
I use it as the final step for my lecture recordings, which have been disassembled with ffmpeg, edited with Audacity, encoded with Handbrake, and finally reassembled using ffmpeg. LosslessCut combines the speed of ffmpeg with a quick and pleasingly minimal UI.
Sort of related - anyone know of an open source tool that can repair video streams that get broken during the download process (using youtube-dl) due to internet interruption.
Everything I've researched into this says that it cannot be done because there is final metadata that gets added at the end of the stream that is missing. This does not seem right - if you have already download frames of video there should be some way to recreate any metadata instead of being left with an unplayable broken mpg file.
The internet has many shady third party paid products that claim to do this but I don't trust them.