Bug 419201

Summary: Red artifact when rendering very short title clips
Product: [Applications] kdenlive Reporter: inFlowia Lab. <inFlowia>
Component: Video Effects & TransitionsAssignee: Vincent PINON <vpinon>
Status: RESOLVED FIXED    
Severity: normal CC: julius.kuenzel
Priority: NOR    
Version First Reported In: 19.12.3   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description inFlowia Lab. 2020-03-24 21:24:58 UTC 
SUMMARY
If the title clips are very short (only 3-4 frames long) and one of them has a “distort” effect with animation on key frames, then when rendering, a red screen on the finished video may occur at the junction of such clips.

SOFTWARE/OS VERSIONS
Linux: UbuntuStudio 19.10 x64
Appimage

ADDITIONAL INFORMATION
I could get rid of this artifact only by shortening the beginning of the clip that goes right after the shortest clip.

I tried version kdenlive-19.12.0a-x86_64 but it turned out the same.

Perhaps the problem is due to the incorrect use of the "Distort" effect preset. I noticed that the effects to which you apply the preset do not behave normally - their regulators can become inactive after applying the preset, and then become active again after a while. Maybe this problem is related to this.
Comment 1 Julius Künzel 2021-03-17 20:01:52 UTC 
Can you please update to the latest version (20.12.3 at the moment, https://kdenlive.org/en/download/) and report here whether this is still happening?
Comment 2 inFlowia Lab. 2021-03-19 09:18:33 UTC 
(In reply to Julius Künzel from comment #1)
I checked it on a small freshly created project with seven clips and music - everything is in order. There are no artifacts.