Tool to trim, cut, merge video files

[galapogos]

Hi,
I'm looking for a free/open source tool that allows me to trim, cut and merge mp4/mkv files. Eons ago I used VirtualDub, and a few years ago I switched to avidemux (can't remember why). It works perfectly to trim and cut single video files, but when I merge different video files, the merged video gets corrupted apparently from the merge point onwards, even though the audio/video encoder, resolution and frame rate are identical.

What can I use to achieve this? Thanks!

[Selur]

..., but when I merge different video files, the merged video gets corrupted apparently from the merge point onwards, even though the audio/video encoder, resolution and frame rate are identical.

video encoder/format being the same doesn't mean that the video streams are compatible with one-another.

What can I use to achieve this?

Live with the fact that some things are not possible without reencoding. To understand it, you need to have a basic understanding of audio/video formats and containers.

Cu Selur