Black border around scaled strip with alpha over When downscaling a strip in the VSE, black borders appears around visible edge pixels.
This is noticeable when overlaying (alpha over) the strip into a lighter background.

In this example, a yellow color strip is scaled down. The transform effects strip is scaled down and the mode is set to alpha over. Below both is a white color strip. Dark borders are visible at the edge of the strip.


This is also the scale with scaled normal images.


Most solution to similiar posts (this, this) suggest using masks, which may work in some cases, but appears to be a workaround rather than a solution.
The transform strip appears to not handle premultiplication/alpha over correctly with the bilinear.

No borders are visible with the cubic interpolation mode.