How to "letterbox" a video to a wider aspect ratio? I have a source video file that was shot for TV (4:3 ratio), and I would like to resize it for 16:9 ratio displays. How can I add the appropriate amount of black letterboxing on the sides so that the source video is not stretched/distorted?

In the screen shot here you can see I have cropped the video clip slightly to get rid of a few extra black pixels on the sides and top of the video. This is just to get a more symmetrical, clean cropping. Next I need to add the correct amount of black space on the sides to prevent stretching but I'm unsure of how best to do this.



Thanks in advance for any help!
Set the render dimensions to what you want the output video to be, for example 1920x1080.

In the VSE, add an Effect Strip of type Color as channel 1, and adjust its length to match the video (you can go back and adjust this after adding the video, in the next step)



Add the video to channel 2, and set Blend to Alpha Over. Enable Image Offset and adjust the offset until the video is properly placed. The cropping that you're also doing, works well together with the offsetting, just remember to use the cropped size, not the original size, when you work out the offset.