Small question: Is there any other way to adjust the output of the movie viewer plugin besides black threshold and skip over initial frames?
I've adjusted the black threshold and found that ideal is 80 - 90% but there are issues it doesn't solve. Thumbnails containing opening credits / text, thumbnails that are mostly or all white (either from a flashback or just a white screen at some point in the video), and thumbnails that don't really contain anything of significance.
Those are the only options in the plugin itself, other than telling it not to generate thumbnails at all and falling back on Windows or other movie thumbnailers that have been installed.
You can always try Icaros. Instead of finding the first non-black frame, it can go by percentage or timestamp.
Icaros generates very good thumbnails but the problem is they can't exceed 256 x 256 in any single dimension as far as I'm aware. This means for content that is 16:9, the preview size is relatively small.
Unfortunately the windows thumbnails are too small.
I've been trialing XYplorer and they seem to also let windows generate thumbnails but they always fit the size of the thumbnail to the size you specified for your thumbnails so you can get larger than 256 x 256. I don't know what you'd call that, fill without cropping / stretching?
It seems to depend on the file here. Some videos (even with the same extension) get 512x512 (or maybe more) thumbnails from Windows; some seem to be limited to 256x256. I'm guessing it's using an embedded thumbnail in some cases, or maybe it depends on the video resolution.
An option to enlarge small thumbnails to fit the thumbnail size is on our to-do list.
That's huge Leo, thank you 