Hello.

I use Kdenlive for professional work and have been experiencing an odd string of bugs during the past four months in Kdenlive 18.04 on KDE Neon.

1. Are MLT clips supposed to condense to only one frame when speed effects are put on them? For example, if I stablize a clip, kden generates an mlt file. If I take that clip, put it in Kden and apply speed, the clip will shrink to only 1 frame in size, become unmovable, and cannot be stretched back to normal size. When the speed effect is removed, the clip still remains only 1 frame long and says that the clip is invalid when I try to move it.

Why do clips become corrupted, invisible, stay in a position in the timeline despite clip being moved?
Occasionally, I run across an issue where the timeline and the viewer no longer show the same information. I move clips around in the project or use M to slide them, but the viewer only shows the project the way it was before I moved the clips. Is this a cached render issue where updates to the timeline don't reflect what Kden is displaying in the monitor? Also, sometimes clip will simply become 'Invalid' and refuse to move, recieve effects, or display properly. This happens occasionally when moving the clip around on the timeline.

Why is it when Kdenlive file is saved and reloaded, recent changes are not saved? Often when I save, then immediately close the program, then reload my Kdenlive project, the most recent changes do not show up.

Why is it that Position and Zoom, Rotate and Sheer, and other Transform effects change scale over time? Using Kdenlive for professional 4k editing has been a strain since any transformation tool causes clips to misbehave. At first, everything runs good. I place position and zoom on a clip, scale the clip to a certain size, and apply some keyframes. But, over time, the scale changes on all clips. For example, if I set the effect on a clip, work on the rest of the project for an hour, then come back to the clip, the scale would change from 102% to 48.65% or to 480%. Is there a reason why this happens?

Finally, if anyone knows, I would like some clarification on which settings to adjust in Vidstab stablization, to avoid getting Jello effect (where portions of the clip appear like linear bubbles for lack of a better term).

I realize this is a lot, but any advice would be appreciated. I find that I am spending too many hours cleaning up the aftermath of these glitches, and it is putting a strain on my workflow.

Point 1: I confirm this behavior in version 17.12 and even in version 18.12. In the coming Refactoring version the speed effect is new written and stabilize/speed works like expected. Nevertheless we saw this behavior in the Refactoring version as well but could not reproduce it.

Point 2: Moving clips around should be fixed in refactoring version. The question is: How big are you projects in relation to the number of clips and complexity? Do you work with proxy clips?

Point 3: The saving behavior you have is strange. Copy a project and can you try that with the Refactoring Nightly build (I assume you work on Linux)? https://kdenlive.org/en/download/ .

Point 4: We see keyframe problems since version 18.04 with motion tracking as well. Do you have this problem in version 17.12 as well? This problem should be solved in the refactoring version.

Point5: Do you use the VideoStab with right click on the clip (Videostab2) which is outdated or do you use VidStab under the effects? For VidStab under effect here some explanation of the values: https://www.mltframework.org/plugins/FilterVidstab/ .

Sorry to have no really solution for your problems with the actual version.

Merlimau wrote:Point 1: I confirm this behavior in version 17.12 and even in version 18.12. In the coming Refactoring version the speed effect is new written and stabilize/speed works like expected. Nevertheless we saw this behavior in the Refactoring version as well but could not reproduce it.

Point 2: Moving clips around should be fixed in refactoring version. The question is: How big are you projects in relation to the number of clips and complexity? Do you work with proxy clips?

Point 3: The saving behavior you have is strange. Copy a project and can you try that with the Refactoring Nightly build (I assume you work on Linux)? https://kdenlive.org/en/download/ .

Point 4: We see keyframe problems since version 18.04 with motion tracking as well. Do you have this problem in version 17.12 as well? This problem should be solved in the refactoring version.

Point5: Do you use the VideoStab with right click on the clip (Videostab2) which is outdated or do you use VidStab under the effects? For VidStab under effect here some explanation of the values: https://www.mltframework.org/plugins/FilterVidstab/ .

Sorry to have no really solution for your problems with the actual version.

Apologies for the atrociously long delay in my response, but I have been ill.

In regards to point 2, my projects are generally 1-2 minutes in length. Since the footage I'm working with are 4k h264 MOVs, I use proxy clips. Most of my pojects are not overly complex. Usually I import about 30-40 clips, take between 0.5 -2 seconds from each one and arrange them in a track with some music below. Probably the most complex project we've done recently is this piano repair video here: https://www.youtube.com/watch?v=ttAYajBzjTY

3. I will look into the nightly build, currently I've been using the flatpak from Kden's Download Page.

4. Yes, I remember having keyframe problems in both 18.04 and 17.12.

5. I've been using the videostab2. I thought the vidstab effect was broken (or at least it was back in the Kdenlive 17 versions I used to have). I will take a look at the documentation on mlt's website.

Thank you for the response. This has given me some new ideas to look into.