Size, position and rotate distortion is not precise

Bug
,
1

I am running Windows 10 Pro (64-bit)

I am running the latest version of Shotcut. (25.05.11)

The Size, Position & Rotate filter, when scaling/distorting a video that has an aspect that doesn’t match the project aspect, does not fully fill the scale dimensions. When scaling a thin image/video, like a YouTube short to 16:9, there will be a black bar on the right side of the video, thus making it uncentered. The thinner the image/video, the bigger the black bar will get.

This is a problem when you want to make a vertical “squish” effect with a video; if you scale/distort a video (but only vertically) too much, the black bar will appear and make the video appear off-center

  • Can you repeat the problem? If so, what are the steps?

  • Take a thin video, or image and put it on a track

  • Apply the Size, Position & Rotate filter

  • Scale it (only vertically) to something like (1920, 16) or (1280, 16)

  • The video will then appear off center with a black bar on the right

Apologies if this sounds very confusing, this is me writing my first bug report for Shotcut :/’

2

Thanks for your report. In my test, I had to increase the vertical size from 16 up to about 600 before the distorted image filled the width. This is a tremendous amount of “squish” that you are asking for. Maybe it exploits a limitation in an edge case in the resize algorithm. I will mark this bug report as “accepted”. I do not know if/when someone will try to fix it because it seems like an uncommon thing to do.

3

Update: I did a quick investigation on this. The cause of the problem is a rounding accumulation in the processing.

Workaround: You can set the rectangle width to be wider than the frame to make the image stretch to the extent of the frame. For your example of 1920x16, I had to set the rectangle to 2160x16 to get the image to reach the edge of the frame.