Is there some way to tell Caja what app to use for thumbnails of video files?

I'm using Ubuntu Mate 23.04. I usually use Celluloid to watch videos, and even to listen to those sound files that aren't part of my music collection (I use Rhythmbox for those that are). Now, in addition to Celluloid and VLC, I recently installed Totem (the GNOME video player) as a third video app, because I like the way you can use it to easily create a thumbnail gallery of a video file.

Problem is, since I've installed Totem, although I never set it as my preferred app for anything, Caja apparently tries to use it to create its own thumbnails of video files. And Totem doesn't seem to be good at that- it crashes from time to time, and it leaves some files without any thumbnails.

So, is there some way for me to tell Caja to return to using Celluloid to create thumbnails of video files?

You can change the preferred applications for each of the media types. Open the Control Center and open Preferred Applications to see which applications are set as the defaults. Choose from the list for the apps you want to use to play Audio files or Video files when you double-click the file in caja.


Caja uses ffmpegthumbnailer to generate thumbnails

AFAIK The thumbnailer to use is defined here

sudo pluma /usr/share/thumbnailers/ffmpegthumbnailer.thumbnailer

It should look like this:

[Thumbnailer Entry]
Exec=ffmpegthumbnailer -i %i -o %o -s %s -f

Maybe the Exec and TryExec are totem instead of ffmpegthumbnailer ?


@goinglinux Thank you, but I always had celluloid as my preferred multimedia app in the Control Center.

@tkn Thank you. Looking at that file tells me it's set to ffmpegthumbnailer, as it should be. But it still sometimes happens that, while Caja is generating thumbnails, the process suddenly stops, and I get a popup telling me that "Videos"- which is what my system apparently calls totem- has shut down unexpectedly. And that only started happening when I first installed totem.

there are some things you can try:

ls /usr/share/thumbnailers

and see if there is a file named 'videos.thumbnailer' or 'totem.thumbnailer'
If there is, see if you can move it out of the directory and replace it with a link to the ffmpegthumbnailer.thumbnailer like this

sudo ln -s /usr/share/thumbnailers/ffmpegthumbnailer.thumbnailer /usr/share/thumbnailers/videos.thumbnailer

Other things to try (in order):

  1. remove/purge the totem/videos application temporarily
  2. run apt install --reinstall ffmpegthumbnailer
  3. check if videothumbnails are generated.
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