

not sure exactly what features you need but there are
- losslesscut
- avidemux
- mkvmerge and mkvmergegui
if command line is OK, ffmpeg is the most versatile and customizable and tons of support docs and question forums (superuser, stackoverflow, askubuntu) for every conceivable niche one-off operation
i thought Firefox translator didn’t have and East/Southeast Asian languages besides Vietnamese (because of Roman characters) so far