Bug 384797

Summary:	UI Freezes 100% CPU usage of 1 core while clicking on clip with spacer tool in large project
Product:	[Applications] kdenlive	Reporter:	bugs
Component:	User Interface	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	carion.nicolas, french.ebook.lover
Priority:	NOR
Version:	17.08.1
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:

Description bugs 2017-09-17 16:02:57 UTC

In the current 17.08.1 version of Kdenlive I have a very large video project lasting around 3 hours. Now I want to insert some clips to the front of it.

If I click on the spacer tool and then select a clip which is in the first couple of minutes of the project with around >200 clips behind, the UI freezes and uses 100% CPU of one core of my system. After a few _minutes_ the clip and all the following clips are selected.

Dragging the clip with all its followers also takes minutes while the UI is frozen and 100% CPU of one core is used.

I do not know what kdenlive is doing (calculating) that lasts this long, but there is definitely a bug in it because it shouldn't last that long. I do not know how I can add some clips between others in my project now because it always freezes kdenlive once I select a clip with many followers in the timeline.

Comment 1 carion.nicolas 2017-09-20 11:30:43 UTC

This won't fix in the current version of Kdenlive, but will probably be better in the next, because of significant rewrites of that part of the code.

Please stay tuned and give it a new try when the new version (probably 17.12) is out.

Comment 2 bugs 2017-09-20 12:03:05 UTC

Thank you for this information. Is there any preview version of 17.12. that I could use to move my clips around? And more important: if such a preview version exists, is it compatible project-wise with the 17.08.1, so afterwards I can open it again with the older version and continue editing there?

Because its really annoying to wait for minutes until something happens.

Comment 3 alcinos 2017-09-20 12:34:31 UTC

Currently, the best way to have a preview of the next version is to build it yourself from git (branch "refactoring_timeline"). We are working to provide some appImage builds but that's not available yet.

Be aware that this is still under heavy development, and important features might still be missing.
Also note that the projects won't be backwards compatible. If you save in 17.12, you won't be able to open in 17.08.

Comment 4 bugs 2017-09-20 13:02:25 UTC

Thank you for the clarification, although this means that I have to wait some time to get the spaces for the clips I want to insert at the beginning of my large project because the movie should be finished before December.

Anyway, I will give it a try with the new version to see if it improves the situation and if not I will create a new bug report.