This video tutorial hammers at how to cut or trim an MP4 video without re-encoding by means of a lossless MP4 cutter - Joyoshare Media Cutter. You can easily trim it and makes no quality loss during the whole process.
Official website:
https://www.joyoshare.com/video-cutter-mac/
Related article:
https://www.joyoshare.com/video-cutting/cut-mp4-without-reencoding.html
