I keep having issues where the preview is showing what I want but when I render the output doesn't include clips that have the transform plugin with the settings set to centre the video.

I made this demo video to show the problem. Sorry about the confusing audio, as I was recording I couldn't hear that the demos were playing.

https://www.youtube.com/watch?v=MO1XWlu ... e=youtu.be

Any ideas? It's driving me crazy!

Can't reproduce on latest Nightly build for windows...
i have made a custom "transform" effect (with 65% of size)
after that i placed the custom effect on track V2
and the output is rendered correctly.. 2 clips with the 2nd one resized by 65%

Thanks for taking a look for me.
I've tried to make a minimal viable demo.

http://mattvenn.net/files/transform-bug-demo.zip

I haven't been able to reproduce the bug identically, but hopefully this will help.

What I'm usually seeing is that the preview would show the effects of the transform, but the render won't.

In this demo, the preview is also broken.

Thanks,
Matt

I think it might be opacity related.
It seems that kdenlive is setting the opacity to 1%

Opacity doesn't seem to do anything from 100 to 2%. But 0% will not be visible, and 1% seems random whether it will render to preview or output or not.
I also see that sometimes it automates the opacity so it is slowly reducing. There are no keyframes, so don't know how this is happening, but maybe if it's at 1%, it immediatly drops internally to 0.99%. It gets rounded up to the interface, but internally, if <1% it won't render anything.

I don't really know, just grasping at straws here. I don't have any examples that solidly do one thing or another.

Matt

right, it's something to do with presets.
So if I save the transform plugin's settings. Then make a new plugin on another clip and use the preset, it will do the failure thing (sometimes).
When it is failing it will never work, but I have no way of predicting if it will fail or not.

If I delete the plugin, create it again, then set all the settings how they were in the preset, then it seems to always work.
So the "work-around" is to never use plugin settings.

I have a comparable problem.

Using Transform to scale my clips to 120 %. Not centered, but aligned to top or bottom and one side. Render shows the first frame of each Transitioned clip after each cut, but no more video.

When reviewing my clips inside Kdenlive, I can also see the freezing repeatedly. Not always, but often.

After switching the visibility of the Transform effect off and on again in the affected clip, it usually shows me the video again without freeze. Until the next run. Then it freezes again.

With a bug like that Kdenlive is unusable for me. When I render the same project with visibility switched off for Transform effect on all clips, there's no freeze.

System (in case that matters):
Kdenlive 19.12.3
Manjaro Linux on Kernel 5.6
Dual Xeon X5690 and Radeon RX580


EDIT:

Ran another test render, with Transform visibility switched on or off on alternating clips. This time I get a black screen instead of the freeze, so I can confirm problems mentioned above.

mattvenn wrote:I think it might be opacity related.
It seems that kdenlive is setting the opacity to 1%
Matt

your locale decimal separator is "," (comma) or "." (point) ?

BTW i can render your demo bug on my system without issues (i switched my separator to point) .. the only alert i have is your custom effect (center face) that i replaced with a standard "transform"

As recommended in this forum I am using the AppImage version of Kdenlive 19.12.3 now. And all problems are gone! Transform works fine!

I even noticed that another issue that I haven't mentioned yet has disappeared:

I placed a JPG in the video stream, and its brightness changed as soon as the Wipe composition set in. Switching between "Alpha" and "Overlay" in the Wipe setup didn't change that behaviour. (This setup option is no longer there in the AppImage version.)