Ok, here’s my new proposition.
Your images all need to have the same ratio.
Since cropping is not a good solution for you, there is still a way to make them all have the same ratio.
Solution: Imbed each of your image in a transparent frame that will have the same aspect ratio as your project.
For that you’ll need Photoshop, or Gimp. There are also online tools you can use, like PhotoPea.
- Create a new file that has the same size and aspect ratio as your Shotcut project.
Mine is 1920 x 1080. - Choose the Transparent background option.
- Drag-in one of your images
- Resize/position it if needed
- Export as a PNG with transparency,
- Repeat with all your images.
Now that all your images have the same size as your project, you wont get that black bars problem anymore. That means you won’t need the SP&R filter anymore on the track head.
There is still a small problem though. The blurred part of the Bar Horizontal transition is semi-transparent, revealing the pink color from the track below. Maybe this is not a big deal for you. If it is, reducing the blur level (Softness) of the transition helps.