I did write a script for this a while ago. Its still available on this post; https://hummy.tv/forum/threads/thumbnails-any-configuration.3241/page-7#post-43892
The parameters are at the top of the script, so it could easily be automated (or changed or ignored)
I've been running it as a cron job for years, and am very happy with the results.
The only issue is sometimes you get a failed (largely grey) thumbnail, but there doesn't seem any good way around this.
One of the options is to process in a slow mode for SD broadcasts when this happens (which usually works), but for HD it is probably too slow.
The parameters are at the top of the script, so it could easily be automated (or changed or ignored)
I've been running it as a cron job for years, and am very happy with the results.
The only issue is sometimes you get a failed (largely grey) thumbnail, but there doesn't seem any good way around this.
One of the options is to process in a slow mode for SD broadcasts when this happens (which usually works), but for HD it is probably too slow.