Bug 449370

Summary: Add custom playback speed to render slow-motion videos within digiKam.
Product: [Applications] digikam Reporter: Jens <jens-bugs.kde.org>
Component: Preview-VideoAssignee: Digikam Developers <digikam-bugs-null>
Status: REPORTED ---    
Severity: wishlist CC: caulier.gilles, metzpinguin
Priority: NOR    
Version First Reported In: 7.6.0   
Target Milestone: ---   
Platform: Appimage   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Jens 2022-01-30 14:23:27 UTC 
SUMMARY
My smartphone (and many other smartphones) can record "slow motion" videos at 240fps and even 960fps. When being played back within Digikam, these vidoes are  played back in "realtime" with 240fps, which is formally of course correct, but the viewer does not experience the "slow motion" effect.

I would like to be able to tell Digikam that *certain* videos (not all) should have a custom playback speed, for example 30fps, despite what is set in the video file. This way, videos recorded at FPS >>30 are shown as "real" slow motion videos, and timelapse videos recorded at 1fps or even less would also be shown correctly - but videos recorded at 23.9fps, 24fps, 25fps or 30fps or 60fps (typical playback speeds) are played back with their true speed.

This can be manually set per video or automatically set during import using a filename glob (in my case it would be "SL_MO_*"), but it should be saved with the video metadata so you don't have to set it again each time you play the video.
Comment 1 caulier.gilles 2022-01-30 16:42:08 UTC 
I'm not sure if QtAV frame has the API to change the playback speed. I'm sure that ffmpeg backend can do it. We will seen...

Gilles Caulier
Comment 2 caulier.gilles 2025-12-25 08:37:11 UTC 
Jens, 

With the Qt6 version of digiKam, we already support the customization of the frame rate while video playback. This do not solve this issue ? 

Best regards

Gilles Caulier