Install kffmpegthumbnailer by entering the following commands in the terminal:
sudo apt update sudo apt install kffmpegthumbnailer
Description:
video thumbnailer for KDE
kffmpegthumbnailer is a video thumbnailer based on ffmpegthumbnailer. The thumbnailer uses ffmpeg to decode frames from the video files.
Homepage: http://www.kde-apps.org/content/show.php/kffmpegthumbnailer?content=117562
Version: 1.1.0-0ubuntu8
Section: universe/kde