Bug 442631

Summary:	motion tracker: re-analysis after reset does nothing
Product:	[Applications] kdenlive	Reporter:	Pierre Nerzic <pierre.nerzic>
Component:	Video Effects & Transitions	Assignee:	Vincent PINON <vpinon>
Status:	RESOLVED FIXED
Severity:	normal	CC:	julius.kuenzel
Priority:	NOR
Version First Reported In:	21.08.1
Target Milestone:	---
Platform:	Debian stable
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:	21.12
Sentry Crash Report:

Description Pierre Nerzic 2021-09-18 06:06:46 UTC

SUMMARY
In Motion Tracker effect, only the first analysis works: the progress bar fills, then the "tracking data" button and link appear. But after that, when I want to change a parameter (algo, spacing) and redo another analysis, almost nothing happens: I can see the bar filling much quicker, but the "tracking data" button does not re-appear.


STEPS TO REPRODUCE
1. Add a Motion Tracker effect to a video clip
2. Click Analyze
3. Click Reset
4. Click Analyze again

OBSERVED RESULT
The Tracking data button and link do not appear. They show only the first time, before reset.


EXPECTED RESULT
I should be able to do any number of analysis, with different parameters (tracker algorithm and keyframe spacing). 


SOFTWARE/OS VERSIONS
Windows: not tested, but I will
macOS: cannot test
Linux/KDE Plasma: debian stable
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
As a work-around, I just have to restart Kdenlive to be able to do another analysis. I tried to remove the Motion Tracker effect, then to add it again but it does not seem to always solve the problem. I suspect some cache to remain, blocking next analysis.

Comment 1 Pierre Nerzic 2021-09-25 15:04:07 UTC

After some experiments, I must add some informations to my report. First, it does not happen with every footage. I am not sure, but it may be related to the duration of the sequence. With a less than 7 seconds clip, the problem does not happen, but appears with a 10 seconds clip: only the first run of the Motion Tracker effect is successful, and after a Reset, next analysis do nothing and terminate much quicker.
I would like to get some detailed log inside Kdenlive, to be more helpful.

Comment 2 Julius Künzel 2021-09-27 13:46:42 UTC

Thanks for your report! Please try the nightly version of Kdenlive (kdenlive.org/downloads) because recently there have been several fixes for the motion tracker. These fixes are going to be in 21.12 stable release. Does the reported problem still exist in the nightly?

Comment 3 Pierre Nerzic 2021-09-28 06:40:12 UTC

Hi Julius,

I tested with the nightly build and I can confirm, the bug has been solved. It now works very well. We can close and forget this ticket.

I saw many improvements in this build. It gives me a lot of ideas: zoom into the area enclosed by the tracking, and more generally link to an effect whose area is delimited by the tracking.

I also found a discussion, https://invent.kde.org/multimedia/kdenlive/-/issues/1155 reporting exactly the same problem. I am sorry, I was not aware of this website, the bug report form always forwards to bugs.kde.org, where, I was sure, there was no report about my problem. If I knew about invent*org, I would not send such a duplicate report :-)

Have a very nice day!
Pierre

Comment 4 Julius Künzel 2021-09-28 07:46:20 UTC

Hi Pierre,

bugs.kde.org is the preferred place for bug reports so you did everything right! The issue tracker on invent.kde.org is mainly used by team members and user that test the nightly version even though we don't have a very strict concept on that and exceptions happen. In general it is better to have duplicate report than don't have report at all, but of course avoid duplicates is a nice thing as it saves work and if you are aware of both trackers that's really great!

Thanks again for your report!
Julius