Not generating preview thumbnails

[LuciusAezerith 0]

Hi I recently started using Emby, while creating the new library I enabled the preview thumbnail feature with these settings

After it had discovered all my files in the library I ran the scheduled task manually this took a while but when I go to play one of the episodes it doesn't show me any previews, weirdly enough it does show me the previews on some other episodes.

If I check the logs it appears that it succeeded on all the episodes.

and if I try to run the scheduled task again manually it completes in 0 seconds.

I'm running the server on docker with the official Emby image.
Thanks in advance for any help!

[richt 94]

I've had problems with this and asked a few questions.  Here are some pointers I picked up.

The "when media is added" option can be tricky, especially if it is a new recording and a .ts file.  It appears this file format doesn't work well if the thumbnail process starts running while some other post processing task is running or if the file is being accessed (still open).  As a result I changed this to only generate the thumbnails on a scheduled scan.  I added multiple scheduled tasks to accommodate my recording patterns and post processing tasks.

Also to get Emby to generate thumbnails for a file that is being overlooked on subsequent scans, you must perform a metadata refresh, replacing the metadata and images on the particular file. 

These quirks are annoying, but at least you can take some action to work around them. 

[LuciusAezerith 0]

Thanks for the pointers I'll keep those in mind if I ever stumble on some problems with that as well, especially the way how to get Emby to generate thumbnails for files that are being overlooked will be usefull.
I think I've found the problem after digging trough the logs for a bit. Apparently Emby didn't have the proper user assigned to it in Docker, I'm used to assigning the user and group with PUID and PGID from using a lot of the linuxserver.io images but the official Emby image uses GID and UID instead. That and setting it so that Emby stores the .bif files next to my media files seems to have fixed it for me.

Edited November 14, 2023 by LuciusAezerith
punctuation

[Luke 42077]

Thanks for following up.

[bradcook 1]

I have a question about thumbnail generation before I go through my entire library. Will refreshing metadata cause Emby to generate preview thumbnails for locked (metadata locked) titles? I have a lot of titles that I've altered the sort order for and I've got them locked. I'm planning on locking all titles before I refresh metadata but I'm not sure if this will cause the title to be overlooked when refreshing metadata to prompt Emby to generate thumbnails.

[Luke 42077]

49 minutes ago, bradcook said:

I have a question about thumbnail generation before I go through my entire library. Will refreshing metadata cause Emby to generate preview thumbnails for locked (metadata locked) titles? I have a lot of titles that I've altered the sort order for and I've got them locked. I'm planning on locking all titles before I refresh metadata but I'm not sure if this will cause the title to be overlooked when refreshing metadata to prompt Emby to generate thumbnails.

HI, the video preview thumbnail feature (for skipping), does not look at the lock status so that shouldn't be a problem.

[bradcook 1]

Awesome. Thanks!