installed Leap 15.6 from scatch yesterday. Playing around, I find that to generate video preview thumbnails, Dolphin seems to well trigger ffmpegthumbs (it’s well activated and set to scan unlimited file sizes) since my harddisk starts rattling and some video thumbnails appear inside the folder symbols of Dolphin, but not a single thumbnail is displayed for individual video files. Very, very strange.
As this seems like an external drive did you check this setting:
Dolphin-> Einstellungen->Dolphin einrichten->Interface->Vorschauen-> Keine Vorschauen erzeugen für Dateien auf Fremdrechnern
No, it’s not. It’s a local USB-connected drive, even defined in fstab.
And as I said, the drive starts rattling along and some thumbnails DO appear.
T.