Although I enjoy having thumbnails for videos, it too often shows spoilers!
Is there a way to define what thumbnail is used for a video? How is it set in Plex?
Ideally, I’d pick a thumbnail early in the video…
Are you taking about the thumbnail previews taken every 2 seconds, or the single thumbnail for each tv episode?
Are you talking about
- the background thumbnails,
- the chapter thumbnails (that you can activate under scheduled tasks) or
- the video preview thumbnails (scheduled tasks too)?
For the background thumbnails you could put a spoiler-free fanart background to the directory.
You can set a higher frame interval for the thumbnails in the Preferences.xml file.
Change the value for GenerateBIFFrameInterval from default 2 to something higher to reduce the chance of displaying spoilers.
For chapter thumbnails you can disable them under settings>library>create chapter thumbnails and set it to never.
On the same place you can disable the video preview thumbnails by setting the generate video preview thumbnails to never.
Hope this helps! 
If you mouse over the episode thumbnail on the web/PC interface there is a pencil there.
Click it to edit the metadata for the episode and there is a poster tab on the left side.
You can choose from the thumbnails here for something that wont be a spoiler, but the selection will vary greatly depending on the popularity of the show.
If you don’t want to see the thumbnails prior to watching the only thing I can recommend is using a client that has the option to blur or hide thumbnails of unwatched media.
Thanks for the replies!
I realize I should have detailed more…I’m talking about thumbnails that are displayed when you browse a library of ‘Personal Media’ where I mostly put sporting events that I wasn’t able to watch live.
So seeing the thumbnail of e.g. a boxing match where you see the guy carrying the championship belt around his waist, kind of spoils it 
.
That’s why I was hoping there was a way of displaying a thumbnail much earlier in the video, (e.g. first few minutes)
