Stabilization get mad if using fadein or fadeout video on the clip

What is your operating system?
win10

What is your Shotcut version (see Help > About Shotcut)? Is it 32-bit?
22-12-21

Can you repeat the problem? If so, what are the steps?
Long months to understand this bug, but finally I’ve realized the process (or I’m supposed to.)…
Stabilize filter is applied and compiled to the clip that results from other filters and of course the speed of the clip (1x, 0.9x, 0.8x, etc).

Stabilization checks the image in squares (usually corners) and tries to keep them as fixed as possible using a bit of zoom to move around the image, in order to attenuate the camera movements.

If you apply a fade-in or fadeout effect before analyzing the clip, the analysis of the image registers the total or partial black of the fade and doesn’t have the reference points to keep fixed. In fact, I get a camera flickering during fade if I use one of those filters with stabilization.

The first solution is to push ANALYZE from the stabilization filter without using any fade operation, but in general, without applying any type of obfuscation of the image.
Once the analysis is done, you can apply any other filter, but you cannot “cut the clip”, because a new stabilization analysis would be required.

Second solution: stabilization should avoid during analysis some specific filters, like fadein/out, that make it go mad, but this could be hard or even impossible while shotcut add new filters at every new version. Moreover, stabilization should be applied to the clip considering a change of speed, and I’ve noticed a good work compensating the loss of framerate with lower speed, and this is appreciated. So the solution is not to consider the original clip, because speed and some colors correction must be considered during analysis.

In conclusion, I’ve not figured out hot how to prevent stabilization to get mad, but maybe, one of you can think about it. Idea are appreciated.

best regards
LHN

We could probably make it avoid fade in video, but it would not detect someone doing the same thing with keyframes on brightness, color grading, hue/saturation/lightness, etc. Of course, the clip could have fades already baked in as well. Instead waiting to add fade or other filters you can disable them.

Yes, maybe the point is just to inform the user that some filters could lead to wrong stabilization and should be deactivated by the checkbox, before the analysis begins.
This could be done with an Ok/Cancel popup question, but the choice must return to the user…

In other words, there is not much to do…

Well, instead of the popup question, maybe, a warning box with yellow icon and the list of dangerous filters of that clip, inside the stabilization filter box, could improve the learning of when and how run analysis…
Is that good?