Bug 405054

Summary: [refactoring_timeline] image clip not consistent between timeline preview and high quality with transform applied
Product: [Applications] kdenlive Reporter: thompson <kolloom>
Component: Video Effects & TransitionsAssignee: Vincent PINON <vpinon>
Status: RESOLVED FIXED    
Severity: normal CC: fritzibaby, kolloom
Priority: NOR Flags: fritzibaby: timeline_corruption+
Version First Reported In: git-master   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: image clipping

Description thompson 2019-03-04 03:03:09 UTC 
Created attachment 118519 [details]
image clipping

kdenlive 19.03.70
mlt 6.13
ffmpeg 4.0.2-2
git repo branch origin/refactoring_timeline 76bca9ab6

STEPS TO REPRODUCE
1. add an image to timeline
2. switch timeline composition to preview
3. apply a transform effect on the clip. 

OBSERVED RESULT
under preview, the image moves slightly downward, results in image clipping. 

EXPECTED RESULT
the image should stay in the same position under preview and high quality composition.
This can be reproduced with 18.12.1 as well. 

There is a slight difference even without the transform effect, but i think that is just the resolution between the two modes.

SOFTWARE/OS VERSIONS

KDE Frameworks Version: 5.55
Qt Version: 5.11.1
Comment 1 emohr 2019-03-04 18:38:23 UTC 
Confirmed. Tested with nighty_build AppImage #100. Your setup: PNG above a clip with transform effect.

Switching timeline between “Preview” and “High Quality”.

- If the PNG has an alpha channel it jumps. 
- If the PNG has no alpha channel it stays.

Opend issue: https://invent.kde.org/kde/kdenlive/issues/84
Comment 2 emohr 2019-03-06 19:39:24 UTC 
PNG with alpha only jumps when the PNG with alpha has not the same size as the project size.

As work around: make sure the PNG with alpha has the same size as the project size.