Jellyfin keeps starting a process

[Kasper]

Hi, i need some help. Jellyfin keeps on starting a process called FFmpeg.exe i think its because it is processing something like a tricker image but i cant see the process happening and the active process is keeping me from ejecting my external SSD. it could be really helpful if you guys could either answer me how i can shutdown the process or how i can watch it and see how far it is to be done.