VidCutter, in my opinion much better than LosslessCut as it's more user friendly and has a simple UI and does exactly what you're looking for. It also has dark mode which I don't think LosslessCut has.
Or.. if you're cheap/hard on money you can try Shotcut which is a really nice video editor with lots of extras and it's workflow is easy to learn, plus.. it's free!
You should also pick up Vidcutter as it's a really helpful video editor that can snip pieces of video clips and spit out a new file without re-encoding the new bit. For example, I let my Radeon ReLive recorder run while I play and can sometimes end up with files that are several GB in size, however there's only like 30 seconds of video that I want to keep out of that huge file. With Vidcutter I can just snip out that little 30 seconds and throw away the rest of the huge file thereby saving tons of hard drive space; all without re-encoding... and the best part - it's free!
I have a link here for VidCutter (I have not tried it myself), and it seems to be geared towards your needs.
Having said that, ffmpeg does what you need with ease (assuming that using the command line and writing scripts doesn't scare you) and without fail, regardless of your video format.
A bit more complex but with a UI, there is the Video Sequence Editor inside Blender (the 3D package). It also handles almost any video format, but is far from traditional when it comes to video editing.
All the usual suspects for Linux (Shotcut, KDEnLive, OpenShot, PiTiVi) are mostly trash. but don't take my word for it, go and try any of them.
I have been an editor for close to 20 years now and I can tell you that there is no perfect editor, they all have faults (FCP, Media Composer, Premiere, Vegas Pro, Resolve, Edius, Catalyst, Lightworks, etc).. however when it comes to Linux, it is sad to accurately generalize and say that there is no video editor worth using.
Anyone who says otherwise probably thinks that editing is simply loading a clip, applying an effect, change in/out and export.
Sure, some programs (lightworks, Resolve) may work under linux, but only under very specific environments (CentOS) and with specific hardware... and even then they do not run as well as their Windows counterparts, and there is a lack of professional editing codecs under linux.
This is a real shame, because Video editing and to a degree, photo editing, is what keeps me from fully committing to Ubuntu, and I hate it every time I must switch back to windows to get Video/Photo work done.
I remember when /u/ChrisLAS trimmed some clips with avidemux for LAS 453 and the end result wasn't good at all. That's because avidemux doesn't transcode the clips so it goes to the nearest i-frame it can find.
VidCutter is a Qt5 application (written in Python 3 and uses ffmpeg and mpv) that can be used to trim videos without transcoding as well. By trying it out I noticed it could trim the video files pretty accurately. Not sure how it's being done.
Version 3.0 was just released and it's in the AUR as vidcutter
and vidcutter-git
for latest snapshot. There's also a PPA ppa:ozmartian/apps
, a package for fedora 25 (requires some work), an AppImage, a DMG image for Final Cut OS and an installer for Windows as well.