PCM / MTS - something missing?

Nextcloud version 13.0.6
Nikon D7200

Hey, I have 2 problems.

  1. I can’t play files with .MTS
  2. My Nikon Video files (.MOV) has a PCM audio. The video is playing nice, but without the sound.

I remember that something like (mime…?) could be a solution. But I can’t find the right place to edit the nextcloud config. Below u can find a link about one of my video with missing sound.

Thanks for your help.