If you can move to 2.93.4 it will be to your advantage because a number of Video Sequence Editor bugs have been fixed. In this case, it's very easy to do: Use the Crop settings to select the cropping you want. Here I simply cropped 100 pixels off of each side and the top and bottom. This leaves the image centered. Use the Transform -> Scale X and ...


Look at the right side of your screenshot where it says Effect Stip. Size X, Y is the size of the blur. You need to increase the value to something higher for the blur to take effect.


You can do it like this: Important for the image strip: Change the blend mode to something like alpha over: result:


So I have explained why gaussian is not working in comments and it is simple as you just nned to set size X and Y to some value, but for that part "Also, how can I have two videos: one for before effect and one for after effect, like the documentation screenshot below?" Just use this settings in one of your previews, you need to select channel that ...

Only top voted, non community-wiki answers of a minimum length are eligible