Install ffmpegthumbs by entering the following commands in the terminal:
sudo apt update sudo apt install ffmpegthumbs
Description:
video thumbnail generator using ffmpeg
FFMpegThumbs is a video thumbnail generator for KDE file managers like Dolphin and Konqueror. It enables them to show preview images of video files using FFMpeg. . This package is part of the KDE multimedia module.
Homepage: http://www.kde.org/
Version: 4:17.12.3-0ubuntu1
Section: universe/kde