This is a simple Bash script that will loop through every video file in the directory that it is executed in and create a thumbnail with a "-thumb.jpg" added to the filename. It uses ffmpeg to create this thumbnail and will either make a "meaningful" thumbnail for the video file or you can set a timestamp. This is useful for creating thumbnails that reflect title screens or some other useful information. I created this small script to make thumbnails for videos that I host on my Jellyfin server.
The default action of this script is to create a random thumbnail. If you pass the -t flag it'll allow you to set a timestamp. If you pass the -f flag along with the name of a file, it'll create a thumbnail for just that file.
Create thumbnails for every video in a folder
thumbnail [-h|t] [-f Filename]
options:
-h Show this help.
-t Create thumbnail at a specific Timestamp. (ex. 00:00:05)
-f Filename to make a thumbnail for a single video.