Crop: Source's Center bias behaves differently from v20.07.11 to v20.09.27

[TRA]

A bug was introduced to Crop: Source filter from v20.07.11 to v20.09.13 and was fixed in v20.09.27.

Problem with Crop: Source

Hi, I’m using the Crop: Source Filter to make the recordings from my GoPro (1920x1440, 4:3) 16:9 by selecting the ‘Center’ Checkbox and then using the Center Bias slider to select which part of the image I want to keep. Until now, I just maxed the Slider in the + or - direction, if I just wanted the top or bottom of the image, but after my update to 20.09.13, Shotcut crashes when I move the slider to +136px or more. When going in the negative direction, after reaching -136, a green bar starts…

But with v20.09.27, another bug was introduced where Crop: Source’s Center bias slidebar doesn’t do anything if an image file’s resolution is smaller than the video mode resolution.

Steps to reproduce:

1. Launch Shotcut.
2. Select a video mode from Settings > Video Mode that is relatively large.
   I’ve selected HD 1080p 60 fps for this example.
3. Open an image file that is relatively small.
   I’ve created and opened a 500x500 pixels jpeg file.
4. Apply Crop: Source to the project in Source tab.
   The clip can be moved to the Timeline and the filter can be applied there.
5. Tick the Center checkbox.
6. Move the Center bias slidebar.
7. The image doesn’t move.
   
   

This bug only happens if the width or height of an image is smaller than that of the video mode.

If a relatively large image file is opened in Step 3, and the image moves in Step 7 just as in v20.07.11.
I’ve created and used a 2000x2000 pixels image file for this example.

Additional notes:
A. Tested on Windows 10
B. Tested on two of my PCs that have different CPUs.
C. Happens in v20.09.27 and later.
D. This bug appears to happen with video files, even though I haven’t thoroughly tested.

[DRM]

Good to see you posting again, @TRA!

I hope this means you’ll be here more frequently. Your insight and bug reports would be wonderful to have around here more often especially in the (almost) monthly beta threads.

[shotcut]

This is fixed for the next version.