Bug 419325

Summary:	Random video corruption during transitions
Product:	[Applications] kdenlive	Reporter:	Mike Schmalz <mike.schmalz>
Component:	Video Effects & Transitions	Assignee:	Vincent PINON <vpinon>
Status:	RESOLVED UPSTREAM
Severity:	major	CC:	fritzibaby
Priority:	NOR	Flags:	fritzibaby: MOVIT+
Version First Reported In:	19.12.3
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Mike Schmalz 2020-03-28 06:18:47 UTC

SUMMARY
Overlapping two videos or still images and implementing a wipe, at random during timeline playback, video will corrupt during transition periods. If the problem occurs, moving the timeline back and playing again will often render the transition correctly. Rendering the file also exhibits random video corruption during transitions.

STEPS TO REPRODUCE
1. This occurs with transitions between videos as well as transitions between two static JPEG images. Seems more likely to happen with longer transitions, but can occur with very quick wipes as well. The issue seems to be exacerbated when an involved clip has gamma correction and saturation adjustments.
2. CPU is Ryzen5 3600x, GPU is a new MSI GTX-1650 Super with the nvivia-driver-440 installed on Ubuntu 20.04 LTS daily build. Have updated packages a couple of times with the same result. GPU works as expected when given a workout playing games. GPU Acceleration is on in the program and the test in the program says it is ok and active.
3. I have rendered projects with Windows version with Intel Hardware CPU only and did not see the issue on two other machines.

OBSERVED RESULT
Green and purple hued frames during the wipe, corrupt rendered frames.

EXPECTED RESULT
smooth wipe as usual

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Ubuntu 20.04 LTS Focal Fossa (Development Branch) (all packages up to date)
GNOME 3.36.0


ADDITIONAL INFORMATION
kdenlive was installed from GNOME Software from the GUI.

Comment 1 emohr 2020-03-28 13:57:33 UTC

Please try with the current Kdenlive AppImage version 19.12.3 to see if there are any packaging issues https://files.kde.org/kdenlive/release/ 
 
If the problem/issue doesn't occur when using the AppImage, then it's your configuration or packaging.

Comment 2 Mike Schmalz 2020-03-28 16:05:38 UTC

I will try the latest appimage for my next video which uses much of the same content. I have worked on troubleshooting this some more and determined that the issue seems to not occur when disabling GPU acceleration and converting the project to CPU only effects.

Comment 3 emohr 2020-03-28 16:45:37 UTC

Thank you for the feedback and contribution. 

GPU acceleration is not fully implemented and not stable. Please switch it off for the time being.

We close this bug as it is a upstream issue (MLT MOVIT integration). If it still appears in the latest version, please feel free to re-open it and update the affected version number.