Looking at video editors. My needs are simple. Most important is being able to choose parts of video to save. Have used Avidemux and ffmpeg/avconv. The main problem I have with those solutions are selecting start time is not always exact, sometimes a video begins with many seconds of black. So I’ve been playing with some other options. Namely Kdenlive [probably the most powerful, with most features]. However for my simple needs Flowblade really worked well. Also Openshot very similar but adds transitions which I like also.