In case your goal is to fix the corrupted MP4 files, then do not attempt to edit or overwrite the video in question until you try fixing it. Fixing software helps to recover the file structure of the video that is corrupted and makes it functional once again. The outcome of repair corrupted MP4 largely depends on how severe the corruption is. Read more - https://notchox.com/resources/how-to-fix-mp4-video-not-playing/