Simply Trimming MP4 Videos On Mac [duplicate]
LosslessCut is free and meets these criteria.
You can download it here:
https://github.com/mifi/lossless-cut/releases
I recommend choosing the LosslessCut-mac.pkg file from the latest version available.
One thing to note is that mp4s cannot be cut anywhere but there are “key frames” which are where cuts can be done. Otherwise you risk audio/video being out of sync.