Major problems with PNG transparency

Hi there

I think shotcut is a great program! I actually use the version 20.26.28.
I know, this is a very old one … but I can’t updadate because I am working with a old mac 10.10.5 system on it.
Now, I have major major problems with the transperancy of PNGs.
Very spooky is … when I put a PNG in my timeline, its perfect transperant like it should be, but suddenly
I see only the image of the PNG and the transperant background is all black … and it will stay black!
But if I push the same PNG further right oder further left suddenly its transperant again … but not ther where I want to be it (!)
This drives me crazy… and makes it impossible to work fluently … I have absolutly no idea why this causes so many problems …

I will be very very thankfull for help. :slight_smile:


When reporting something like this you should always provide a screenshot of the whole Shotcut window, not just part of it, as we cannot see what clips you have on each track and what filters you have applied. This maks it very difficult to suggest a solution.

I had something recently that may be similar: I had created a .png file of a dashed line with transparency, and placed it on an upper track. The transparent parts of the .png image showed through correctly, but the “fill” around the .png showed up as black. It was a quick demonstration, and I didn’t take the time to go back to see if there was a setting in Shotcut; I just re-exported the .png file in such a way that it filled the whole screen, rather than just the width of the line.

Again, not sure if this is quite the same, but possibly another data point. I was using version 21.06.29.

Thanks so much for helping me … :slight_smile:
here is one screenshot as an example … the yello fonts should be transparant … one a background …

I have absolutly no clue why … its not showing right

I am not able to reproduce. You need to provide a smaller example or steps of how to reproduce it for us to do anything. A screenshot with more than 20 video tracks with PNG on multiple tracks at the same time is not good example, and maybe that is part of your problem.

For what you have showed, everything is working as it should.
If you’re trying to run an opacity filter on a PNG into nothing for a background, the screenshot you are showing is correct.

Example: The bottom color on one half is black. The other side has no color, nor clip.
This example is how Shotcut works, and is not a bug.
Shotcut version 20.06.28. I couldn’t find the Shotcut version you listed.
For other readers, this is an old version of Shotcut.

Thank you very very much everyone giving me help and advice !
I am sorry for replying late.
I am very much under pressure.
I have create for a special offer every single day a short video about 30 - 40 sec.
I do this during the nighttime so I can run it in the morning.

I really love to work with shotcut, think it’s a great program, easy to handle, an with lots of high professional features. If I can work with my old version, sorry it is 20.06.28 with out no major bugs I will shurely support the development.
But I am having sometimes such a struggle, and I get so angry when these transparancy problems with the png pop up.
The very strange thing is, I never know, when it is going to happen … I can work fluently … everything is perfect … and in the final round … suddenly some PNGs not showing transparancy anymore … I don’t knwo why the heck this happens …
I this case for me is … I delete the fals PNGs export the clip … make a know project with the clip and
place the PNGs again … and oh wonder now it is working …
So sometimes I have to do this 3 times to finaly get the result I want.
This is for shure the probably most wrongest way to handle … but in this situation I haven’t time to think about a solution… I just have to get the things done.

Yeah, probably I use to much tracks … You think this is why I have problems with the PNGs?
I do this to be most flexible … but I am still learning and I am opend for any good advice :slight_smile: that helps me …
Is it correct, that Shotcut not allows to open 2 projects at the same time? To move Tracks from one projects to another one?

I will post some more screeshots to show you exactly where my problems are … So thanks very much for further support …

In this older version you might be running into a problem with filters being trimmed unexpectedly. Select clip and filter and look in Keyframes panel to see if the filter spans the entire range of the clip.

Hi Dan, hi everyone
Thank you very much for answer, and the screens.

The very most important thing for me, is that transparance works! If this should not work correctly I can not use Shotcut anymore.
So If there is a way that these major transparance problemes get fixed, I would be more than thankfull, and willing to pay for the effort, to fix this problem, in this version. Like I told you, that I am not able to upgrade my mac.
The funny thing is, sometimes I have absolutly no problems with tranparance, and then from one day to another it is not working at all.
I do everyday small video clips with shotcut, and I have really no time, thinking about why suddenly the transparancy is not showing.
So if I have a problem, I render the clip, and open up a now file in shotcut, integrate this clip, make a new track and put the jpg or png that was transparent above the clip I just renderd. The the transparance works. But I can’t do that in every single project to get finished.

Here is one example, that even didnt show any “Deckkraft” (in German) means transparancy …
and I just do not knew why ???

I know this is a very old version I am working on … but I am not asking much … just that never ever get in trouble with not showing transparancy. I am working with music, fast cuts, and transparancy I don’t need much more … but this has to work perfectly, otherwise I have to find a another program, but I would regret that very much …

  1. My png 2) the transparancy level 3) my png integrated in the track … 4) no transparancy showing … !!

Another Screen:

Everyhing fine … transparancy is correct

Same track (!)

No transparancy showing at all … !!

Please please get this problemes fixed. Thank you so much.

Transparency and Opacity are two different terms, as you are using the Opacity filter.
The problem is you’re hiding tracks which you are attempting to blend with.

You need to have V1 visible.
Example is using version 20.06.28 (Older version from 2020).

You have nothing to blend with on any track. While you have V1 visible, you have V2 hidden.

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That is impossible. Fixes can only be put into new versions. This problem was already fixed:

Release 20.11.28
  • Fixed Insert Track creates wrong layer/composite ordering (broke in v20.11.25).


Release 20.09.13
  • Fixed video compositing with nothing on video track V1 or V1 hidden.

The latter actually applies to all hidden tracks. Since you cannot upgrade, you can use another program to create and animate your graphics and then use them in Shotcut.

:point_up: Everything above V1 blends with V1 (or the next higher visible track with something on it) instead of some hidden black background track. That is an optimization so that V1 is not always blending as many people only use one video track or have no need for blending. This makes Shotcut much faster; otherwise, for every frame it needs to blend with something or at least check every pixel of every frame to see if it is transparent to skip the blending. So, to fix the problem experienced here, leave V1 visible and ensure there is something there even if you need to remove some video and add a black color clip. Alternatively, in the future, make V1 simply one long black color clip and extend it as needed.

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