It would be best if I describe my project setup first.

I have a bunch of video+audio clips and a continuous audio file recorded with an external mic. First thing I drop the long audio, then match the positions of video clips over it. Then I synchronise the audio with the best precision that I can. Next, I cut the audio without video parts with scissors tool and group video + 2 audio tracks in groups (the grouping is variable, but in general it's easier to have each clip + audio tracks grouped when starting). Then I group everything together, this is like a starting point.

My storyline is completely linear so all I do is basically cut away pieces of clips that I don't want. I do this by marking In and Out points and Shift+X (I cannot remember the funny name this tool is given in kdenlive). It has the effect of what's called ripple delete in the rest of video editing world: the selected part is cut away, everything to the right of it is moved left to close the gap. Excellent.

It's excellent while it works. Unfortunately, pretty often, but not often enough to be an easy to reproduce problem, this falls apart. After a cut, the gap would not close, audio in one of the tracks would maybe offset, a seemingly unrelated piece of video or audio clip would appear to the right of the playhead, IOW not what you expect to happen. After this had happened, all hell is broken lose, undo does not work, trying to move or delete mystery pieces tends to result in error messages (cannot delete/move clip xxx) etc. If I'm observant enough, I can spot this right away, restart kdenlive, reload the project. Sometimes attempting the same cut would result in the same problem right away and I have to offset In/Out points by one frame for it to snap out of it.

I'm sorry for a ramble but it's a very hard to describe problem. If it was easy to describe, I'd just submit a bug report and maybe I will once I figure out the exact way of reproducing it. Does anyone experience the same?

This is kdenlive 17.04.0 on Windows 10. In general the build seems to be pretty stable. This problem however is very nasty. I do not think it's OS-dependent.

Hi snurfel,

Thanks for your feedback. We are aware of some major issues regarding timeline corruptions, similar to the one you described.
There is an ongoing effort to fully rewrite that part of the code, to make sure such things can't happen, and to be able to bring new functions, like advanced trimming (rolling,…)
We are expecting to release a testing version (unstable) this summer and a stable version by the end of the year. Stay tuned !

Happy editing !

Hi alcinos,

Thanks for your effort! I saw a comment for a related bug in the bug tracker last week. Great that you know about the problem because I could not really come up with a reliable way of reproducing it in a reasonable amount of steps. Definitely looking forward to see the upcoming changes. Cheers!

I'm very much looking forward to a solution as well.
Being in the middle of a project (similar type of work as described above) I seem to have some lost clips floating on my timeline I cannot delete or move.

Saving the project and restarting KDEnlive does not resolve the problem.
As there's hours of work in this project I would really hate to have to start from scratch!

Is there any workaround for now?
I wouldn't mind manually editing a .kdenlive-file for now. Or would this just make things worse?

Joost

joosth, I am surprised that reopening the project doesn't solve your problem.
Corruptions happen when the state of the timeline as displayed by kdenlive differs from the actual internal state. If that happens, everything falls apart because essentially there is a discrepancy between what you can actually do and what you think you can do.

However, it is the internal state that is saved to the .kdenlive. Upon reopening, kdenlive reads it again and displays whatever is in there (no problem is known at loading time). That's why when you open a fresh file you shouldn't have any corruption issue.

Could you describe more precisely what happens when you reopen the file ?