Bug 508400

Summary: Dolphin / ffmpeg combo not animating video thumbnails after todays 25.08.0-1.1 update
Product: [Applications] dolphin Reporter: Sylens <oat-lip-confront>
Component: view-engine: icons modeAssignee: Dolphin Bug Assignee <dolphin-bugs-null>
Status: CONFIRMED ---    
Severity: minor CC: aristsakas, bugseforuns, dolphin-bugs-null, nicolas.fella, oat-lip-confront, pinchon.guillaume
Priority: NOR Keywords: regression
Version First Reported In: 25.08.0   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Sylens 2025-08-17 21:57:33 UTC
SUMMARY
I got a big update today, ffmpegthumbs was one of them, to 25.08.0-1.1 and since then my Dolphin doesn't animate the video thumbnails, when hovering my mouse over it. Maybe Dolphin is relate too, i can't tell..

STEPS TO REPRODUCE
1. Start dolphin (btw also version 25.08)
2. hover mouse over a video
3. observe how it's not animating the thumbnail of it..

OBSERVED RESULT
no thumbnail preview animation

EXPECTED RESULT
thumbnail preview animation

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20250816
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1
Kernel Version: 6.16.1-1-default (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-6500 CPU @ 3.20GHz
Memory: 16 GiB of RAM (15.6 GiB usable)
Graphics Processor: NVIDIA GeForce GTX 1050 Ti
Manufacturer: MSI
Product Name: MS-7972
System Version: 2.0

Yes I cleaned the thumbnails cache folder, no it didn't solve the problem. Yes I relaunched Dolphin after cleaning up the thumbnails cache folder.

thanks for fixing it asap, I have many many entertaining vids, and I need to see their contents for my daily ritual "sessions" ;D
Comment 1 Patrick Silva 2025-08-18 13:31:57 UTC
On Arch Linux running Dolphin 25.08.0 the video preview does not change while I hover over the file, but it does when I click on the file.
Comment 2 Sylens 2025-08-18 13:44:27 UTC
(In reply to Patrick Silva from comment #1)
> On Arch Linux running Dolphin 25.08.0 the video preview does not change
> while I hover over the file, but it does when I click on the file.

Yes I also observed this yesterday when I filed this bugreport, however I noticed it's so random, that I don't think the click is related so that's why I didn't wanted to mix it in here cause more (possibly misleading) info can cause the bug fixing progress slower (remember: less is always more) 

Cause sometimes it truly generates on click, sometimes not, sometimes it quickly changes the thumbnail when hovering off of the video, and it appears for like 100ms, so it's very quick - the underlying engine got broken.
Comment 3 Sylens 2025-10-24 16:58:02 UTC
Issue seems fixed, as I'm unable to reproduce this issue anymore as of:

Operating System: Kubuntu 25.10
KDE Plasma Version: 6.5.0
KDE Frameworks Version: 6.19.0
Qt Version: 6.9.2
Kernel Version: 6.17.0-5-generic (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-3470 CPU @ 3.20GHz
Memory: 16 GiB of RAM (15.6 GiB usable)
Graphics Processor: Quadro K620
Manufacturer: FUJITSU
Product Name: ESPRIMO E510

closing ticket.
Comment 4 Patrick Silva 2025-10-24 19:05:13 UTC
On my system the bug persists with certain video files. I haven't identified any patterns yet.

ffmpegthumbs 25.08.2-1
Operating System: Arch Linux 
KDE Plasma Version: 6.5.0
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Graphics Platform: Wayland
Comment 5 Sylens 2025-10-24 20:10:55 UTC
(In reply to Patrick Silva from comment #4)
> On my system the bug persists with certain video files. I haven't identified
> any patterns yet.
> 
> ffmpegthumbs 25.08.2-1
> Operating System: Arch Linux 
> KDE Plasma Version: 6.5.0
> KDE Frameworks Version: 6.19.0
> Qt Version: 6.10.0
> Graphics Platform: Wayland

Hi.

Exit Dolphin and remove thumbnails cache by:
rm -rdf ~/.cache/thumbnails/

Then launch Dolphin and see if it worked.
Perhaps for you those old thumbnails are still there from the "bugged era"
Comment 6 Patrick Silva 2025-10-24 20:35:57 UTC
Thanks. Your steps have solved the bug with some files, but others are still without animated preview.
Comment 7 Sylens 2025-10-24 22:11:35 UTC
(In reply to Patrick Silva from comment #6)
> Thanks. Your steps have solved the bug with some files, but others are still
> without animated preview.

You're welcome. Yepp, you're right, I also observed the same behavior, and closing and reopening Dolphin will make the exact same video to start animating. Regressed bug. Reopening the ticket. Thanks for your feedback :)
Comment 8 Sylens 2025-10-24 22:20:44 UTC
Since ffmpegthumbs strictly interacts with Dolphin, I also redirected this to Dolphin department, cause ffmpegthumbs seems a completely unassigned channel.
Comment 9 aristsakas 2025-12-29 22:31:32 UTC
*** Bug 501552 has been marked as a duplicate of this bug. ***