Transitions darken between videos

[Chris_A_Engleheart_G]

Hi guys I am having problems with my transitions and only happens on certain video files.

I am making a series of drawing video tutorials and I am removing the parts of the video where I am rubbing out mistakes and so I am making transitions between these parts of the drawing. I am finding though that on certain video files the transitions fades (gets darker) slightly which is really frustrating, this doesn’t happen on all the videos but only certain ones, below is an example

Before transition

During transition

After transition

If anyone has any ideas that would be great!

[Ghonich]

Did the light get darker in the original video? The transition would extend the video from the cutting point, so the lighting would affect the transition if you cut the video right before the light change.

Maybe remove about a second of video in both parts and then try the transition again.

[awake]

Do you have the transition set to change only transparency?

[MusicalBox]

I’ve experienced this problem on a few occasions.
Both clips become somewhat transparent in the middle part of the transition. If there is a track below, with a clip, that clip will become visible while the transition occurs.

[Hudson555x]

Try this filter on the transition.

[MusicalBox]

Thanks @Hudson555x. I’ll give it a try it next time I encounter that problem.

[shotcut]

@MusicalBox

Both clips become somewhat transparent in the middle part of the transition

I do not know the cause in the original post, but the Alpha Channel: View filter applied to the transition does not show any translucency:

Also, with the filter removed or disabled, I see no difference when moving the black color clip below on V1 under the playhead or not. It might have something to do with the JPEG on the track above, but I did not reproduce anything.

[MusicalBox]

@shotcut
I just tried to reproduce it with different types of files, but no success so far.
Next time I encounter this problem, I’ll make sure to document it and post a proper bug report.

[Chris_A_Engleheart_G]

So now the problem seems to have vanished and there is no darkening during the transition, must just be a bug thats ironed out by the windows magic of off and on again

[MusicalBox]

Also, in the original post, it looks like the transition is on track V1. So nothing under it.
The original poster says the transition “gets darker”. So I figure that it does get transparent but in his case, it appears like the clips becomes darker.

[MusicalBox]

@Chris_A_Engleheart_G

So now the problem seems to have vanished and there is no darkening during the transition

Hi @Chris_A_Engleheart_G
Did the problem vanish after you close and re-open Shotcut?

[Chris_A_Engleheart_G]

Hi MB it must have done, very strange I know SC has its quirks but this is a odd one

[Hudson555x]

I’m able to duplicate the issue. I used colors from OP’s screenshot.
Shotcut version 20.10.31
Video mode: 1920x1080 30fps
No Proxy, nor Preview Scaling.
Filter on each clip: Size, Position & Roatate

No filter on transition.

fade difference.mlt (8.3 KB)
Source images:

With filter Unpremultiply Alpha applied top the transition:

Here are the color differences:

[Chris_A_Engleheart_G]

Many thanks for this it has really helped! I am still at a loss why it would only affect certain video files though,

[Chris_A_Engleheart_G]

Hi guys so tried the unpremultiply alpha but with no effect, not sure if I have done something wrong?

before

during

after

with-black-colour