Linux Mint 19.1 - Nemo not generating thumbnails.

[Bob Fletcher]

I have done an upgrade from LM19 to 19.1 all seems to have gone smoothly. Unfortunately, I cannot get Nemo to generate thumbnails for video files. I know things have changed. I have clicked the icon on the toolbar but it does nothing. I have checked the size that icons will be generated and 4GB is ample the files I would like the thumbnails for is under 500 MB. The thumbnails previously generated stay in place.

[Bob Fletcher]

BUMP: Nothing so far. My return to LM does not seem to be that good an experience.

[redlined]

I have done an upgrade from LM19 to 19.1 all seems to have gone smoothly. Unfortunately, I cannot get Nemo to generate thumbnails for video files. I know things have changed. I have clicked the icon on the toolbar but it does nothing. I have checked the size that icons will be generated and 4GB is ample the files I would like the thumbnails for is under 500 MB. The thumbnails previously generated stay in place.

hi Bob Fletcher!

I've experienced some hit and miss with video thumbnails being generated in nemo and based on a quick search do see this is a bit of an older looking bug, related to gtk perhaps.

It sounds as if nemo doesn't use ~/.thumbnails rather only ~/.cache/thumbnails and symlink the ~/.thumbnails to ~/.cache/thumbnails may help (but also might double thumbnails if you use another file manager like nautilus)

try this:
sudo apt install mint-meta-codecs (in case you have removed something by uninstalling flash or somesuch)
sudo apt install ffmpegthumbnailer may be useful, the rest is to reset thumbs and symlink .thumbnails to .cache/thumbnails which seems to the broken effect here
rm -r ~/.thumbnails
rm -r ~/.cache/thumbnails
mkdir ~/.cache/thumbnails
mkdir ~/.thumbnails

ln -s ~/.cache/thumbnails ~/.thumbnails Although I do not know if this is best method so testing if things work correct by mkdir ~/.thumbnails may be better option than create symlink from ln -s command mentioned.

I did all the above suggested commands locally, using symlink for /.thumbnails and see my video directory has generated new thumbs in ~/.cache/thumbnails And ~/.thumbnails as expected. (symlink removed and old ~/.thumbnails restored because it was actually way more than expected, lol (see Edit to correct note and quote for more on this:)

I based this recommendation off of three older help threads, which might help you find solution if what I suggest does not work:
https://askubuntu.com/a/616563
viewtopic.php?f=208&t=231128
viewtopic.php?f=47&t=152256#p800264

EDIT TO CORRECT! I used strikethru to deprecate the not so good way to get thumbnails based on this comment: viewtopic.php?p=806167&#p806167
which I see is what happens in effect, ugh...

Interesting: If your ~/.cache/thumbnails folder is empty, first open a folder with some images in it to generate some thumbnails. Now go and look in the ~/.cache/thumbnails/normal folder, and watch as more thumbnails are generated in an infinite loop. This should happen with any file manager, not only Nemo. What's happening, I think, is that the system is generating thumbnails for the thumbnail images that you are looking at, and putting them where they are supposed to go, namely the ~/.thumbnails folder. But since this is actually a symlink pointing back to the folder you are looking at, the new thumbnails show up there, and the system dutifully generates more thumbnails for those thumbnails, and the process repeats ad infinitum.

I do not know how to get nemo to look at ~/.thumbnails directory, it appears to only consider ~/.cache/thumbnails for storing and reference of what to display.

[Bob Fletcher]

Thank for the suggestions Redlined. I have tried it but does not work. However what I have thought of is the following. I did an update from LM 19 to 19.1 it may be that here lies the problem. I am doing to do a clean install. I can't find anyone else with this problem in the current issue. It also only seems to be the thumbnails from the MP$ files.
I will get back to you. First I will run it live and see what happens.

Robert....

[trytip]

what thumbnails you do not see now.

[redlined]

hi Robert!

I do not believe this is an upgrade problem to specific to 19.1 as I did upgrade from 18.3 to LM19beta, then to LM19 release, then to LM19.1 beta and finally to LM19.1 release. But perhaps that path I took to get here left old files from previous version behind that is still used if present or broke if not.

for mp4 files thumbnails are done as expected, I do still get a "hit and miss" for mpeg-ts (.ts file extension=transport stream) though so there may indeed be a bug for system or Nemo when generating thumbnails for some mpeg formats. and may work better for you to convert videos to format that is generating good thumbnails for you, it is what I did some months back based on this thread: https://askubuntu.com/questions/3645/ho ... ing-useful when I found I wanted to try another video player besides VLC which did not understand the .ts file format :/

I also consider it quite a bug that ~/.thumbnails is not used by nemo (unless that is intential by design stuff, but think otherwise as mentioned in other help threads by seeing what nemo does with ~/.thumbnails folder after opening nautilus and it creates thumbnails in that directory versus cache/thumbnails as Nemo seems to use for store but read from ~/.thumbnails