SUMMARY In preview mode Dolphin doesn't display thumbnails for DjVu files. STEPS TO REPRODUCE 1. Open Dolphin 2. Enable preview for DjVu files 3. Go to folder with DjVu files OBSERVED RESULT No .djvu thumbnails generated EXPECTED RESULT .djvu thumbnails generated SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 19.04 (available in About System) KDE Plasma Version: 5.16.2 KDE Frameworks Version: 5.59.0 Qt Version: 5.12.2 ADDITIONAL INFORMATION This may be a regression of bug 326051
Created attachment 121220 [details] Dolphin showing DjVu thumbnails... FWIW, I don't have any problem with DjVu thumbnails in Dolphin using: Operating System: openSUSE Tumbleweed 20190627 KDE Plasma Version: 5.16.2 KDE Frameworks Version: 5.59.0 Qt Version: 5.12.3 Kernel Version: 5.1.10-1-default OS Type: 64-bit
The only way I can make Dolphin show some (not all) .djvu thumbnails is if the .cache/thumbnails folder is shared with another Linux OS (in this case Linux Mint 19.1 Xfce with Thunar) where I don't have problems with .djvu thumbnails. In a VirtualBox with KDE Neon I don't get .djvu thumbnails either, not even when I use Nemo or Thunar. So very likely not just a Dolphin problem.
I installed Tumbleweed on another virtual disk and I'm having the exact same problem: pdf thumbnails are fine, even mobi thumbnails are fine, but not djvu. @Paul: are you sure the thumbnails aren't coming from a shared thumbnails cache?
(In reply to toon.pepermans from comment #3) > @Paul: are you sure the thumbnails aren't coming from a shared thumbnails > cache? Yes, quite certain - I only have openSUSE/KDE on that machine. and the thumbnailers I have installed are: kde-thumbnailer-epub 1.1-1.45 (KDE:Extra) kdegraphics-thumbnailers 19.04.2-1.1 (openSUSE OSS)
Additionally: The thought just occurred to me that the *.djvu thumbnails had likely been in the cache a while, so if the problem was a recent regression I may not have seen it. However after deleting ~/.cache/thumbnails/ *.djvu thumbnails are still being generated correctly.
I do have kdegraphics-thumbnailers 19.04.2-1.1 on openSUSE, but I don't manage to compile kde-thumbnailer-epub there. Compiling did work on Kubuntu 19.04 (after installing a lot of dependencies) but it doesn't make a difference for .djvu thumbnails, which would only be logical for an epub thumbnailer. It would be nice if someone with a fresh install of KDE could confirm if they have the same problem. Although I don't have any idea why a fresh install would make a difference compared to an older one. I installed my Kubuntu two weeks ago on June 16 (and in general very happy with it!)
My initial TW install dates from around May 2015. Sorry, I'm unable to test a new install of KDE, I did however out of curiosity try with a new user, *.djvu thumbnails are OK there also. I guess you'll have to wait until this is picked up by one of the developers, my comments were just FWIW from another end user.
Strange, they work for me too (on Manjaro).
Someone could only just try to boot a recent live USB (or a live .iso in a virtual box) and see what happens. I tried: 1) pclinuxos64-kde5-2019.06.iso in a virtual box (with USB 2.0 enabled so I could plug in a USB drive with pdf and djvu files) 2) a real USB drive with neon-user-20190613-1123.iso on my current laptop (HP Laptop 17-ak0xx) 3) the same USB drive on an old Dell Inspiron 1501 laptop (amazingly it booted just fine but the standard swappiness of 60 is irritating) Each time no djvu thumbnails. On PCLinuxOS thumbnails work out of the box (when selected in Dolphin) for pdf, mobi and (some) epub files. If no one else would have this problem, I really don't understand it. I'm adding a test file in attachment.
Created attachment 121237 [details] test file, Dolphin doesn't show thumbnail on any tested OS
Created attachment 121240 [details] *.djvu thumbnails generated when running live cd Using: http://download.opensuse.org/tumbleweed/iso/openSUSE-Tumbleweed-KDE-Live-x86_64-Snapshot20190628-Media.iso With your document: Biology-of-the-sauropod-dinosaurs.djvu Thumbnails are generated/displayed OK.
Thumbnails work for me too in a Neon live ISO, as well as my Manjaro system. Here's an idea. Go to Dolphin > Control or Settings menu > Configure Dolphin > General > Previews > is "DjVu Files" checked/enabled in that list? Does it even appear there?
That option certainly appears and of course I enabled it. Whether it's enabled or not does make a difference when thumbnails have previously been supplied by another OS (Linux Mint in this case) with a shared thumbnails cache. Then I am able to see the thumbnails in Dolphin, but what still doesn't work then is the folder preview of a folder with djvu files, even if Dolphin can show the thumbnails (supplied by Thunar in Linux Mint) of all the djvu files in that folder. So the most practical thing for me is to go to Linux Mint (which I still want to use from time to time anyway), let Thunar make thumbnails, then go back to Kubuntu, enable djvu thumbnails and disable folder thumbnails (because otherwise the thumbnailer takes a long time examining those folders, and not producing anything if there are only djvu files there).
Does 'ddjvu' work in Konsole?
The command 'ddjvu' didn't work initially, Konsole suggested doing 'sudo apt install djvulibre-bin', and this solved all problems! The missing packages (on Kubuntu 19.04) were: curl (7.64.0-2ubuntu1.1) djvulibre-bin (3.5.27.1-10) libgraphicsmagick++-q16-12 (1.4~hg15916-2) libgraphicsmagick-q16-3 (1.4~hg15916-2) pdf2djvu (0.9.12-1build1) On openSUSE Tumbleweed the only missing package was 'djvulibre 3.5.27-3.3'. Now the question is whether these packages are present on the live images that Paul and Nate Graham are using, or whether they don't need these packages to view djvu thumbnails correctly. Thanks for the suggestion about 'ddjvu'.
addition: The thumbnails still work when I uninstall pdf2djvu, libgraphicsmagick++-q16-12 and libgraphicsmagick-q16-3.
So you're saying that after installing the djvulibre-bin package, Dolphin now created the thumbnails as expected?
That's correct. But it's a mystery to me why I need this specific package and others don't.
That's a good mystery for the Kubuntu people to figure out, since this is clearly a packaging issue and not a code issue. :) Please report it to them. Thanks!
I don't think it's a Kubuntu issue because I had the same problem on every other distro I tested (most in VirtualBox): KDE Neon, openSUSE Tumbleweed, PCLinuxOS and Mageia KDE.
update: I tested the live .iso of Manjaro KDE and here .djvu thumbnails worked out of the box; when I looked at the packages, djvulibre-bin (version 3.5.27-4) was installed. Then I downloaded the latest KDE Neon .iso but again no .djvu thumbnails here, and no djvulibre-bin installed. Version 3.5.27.1-8 was present in the repositories and when I installed it the thumbnails worked immediately after I had restarted Dolphin. So in my case only Manjaro works as expected.