https://bugs.kde.org/show_bug.cgi?id=522852
Bjorn <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |[email protected] --- Comment #1 from Bjorn <[email protected]> --- Hello i also have the same problem and think i have found the root cause. Running `xdg-mime query filetype [FILE]` on both an .mp4 file and an .mkv file gives: ``` bjornbes@fedora:~$ xdg-mime query filetype "/home/bjornbes/Videos/2026-05-08 16-27-26.mp4" video/mp4 bjornbes@fedora:~$ xdg-mime query filetype "/home/bjornbes/Videos/2026-08-28 12-48-03.mkv" video/x-matroska ``` But running `strings` on `ffmpegthumbs.so` to check its embedded mimetype registration: ``` bjornbes@fedora:~$ strings /usr/lib64/qt6/plugins/kf6/thumbcreator/ffmpegthumbs.so | grep -i -E "matroska|mp4|x-msvideo|quicktime" application/x-extension-mp4vapplication/x-matroskauapplication/x-mpegurlqapplication/x-oggwapplication/x-ogm-videoqapplication/x-ogmuapplication/x-shortenrapplication/x-smilx ``` ffmpegthumbs.so embedded JSON only lists `application/x-matroska` and `application/x-extension-mp4v` while neither `video/x-matroska` nor `video/mp4` (the ones from xdg-mime query filetype) appears in the plugin's list at all. So Dolphin's KIO preview job can't find `video/x-matroska` or `video/mp4`, which leads to the problem described. NOTE: ffmpegthumbnailer standalone works fine on the same files `ffmpegthumbnailer -i file.mkv -o thumb.png -s 256`, which confirms this is a KIO plugin's mimetype registration problem and not the underlying decoding. SOFTWARE/OS VERSIONS: Operating System: Fedora Linux 44 KDE Plasma Version: 6.7.4 KDE Frameworks Version: 6.29.0 Qt Version: 6.11.1 Kernel Version: 7.1.10-200.fc44.x86_64 (64-bit) Graphics Platform: X11 Processors: 20 × 13th Gen Intel® Core™ i5-13600K Memory: 32 GB of RAM (31.1 GB usable) Graphics Processor 1: Intel® Arc Graphics Processor 2: Intel® Graphics plasmashell 6.7.4 qtpaths6 2.0 ffmpegthumbs-26.08.0-1.fc44 ffmpegthumbnailer-2.3.0-2.fc44 -- You are receiving this mail because: You are watching all bug changes.
