corrupt files will have glitches in the best case, but more likely have noticeable decoding errors, and completely unplayable files in the worst case (some parts of a video file are essential for processing the rest). that could also happen if the file system metadata gets corrupted, and the OS cannot piece together the file extents or the whole directory anymore.

modern data storage relies on reliable storage medium. to protect yourself against bit rot the only thing you can do is to keep backups on different storage devices. but what does it worth if you don’t notice (in time) there’s corruption. you need some way to detect it. a catalogue of some sort, like a checksum file for a whole directory tree, automatically extended with new files, ran in checking mode on schedule, and notifeably notifying you about issues. it can be a custom made solution for traditional file systems like ext4, ntfs, xfs, the FATs, etc, or a filesystem that has that function built-in like zfs or btrfs. the latter two don’t implement the notification and the schedule part, but they do the majority of the work. also if you want to notice not just corruption but erroneous deletion or modification too, you should also use their snapshot functionality. you can diff them to see if there’s any unexpected changes.