Are you asking how to fit HD (16:9) video into a Standard Definition (4:3) without letterboxing it? If so, then what you want to do is basically “pan and scan”; you scale the video to fit the vertical size of the 4:3 NTSC image and allow the original imagery to fall off screen to the sides. To correct the composition of the image as best as possible the position of the video image is animated to the left or right to make sure the most important parts of the shot remain on screen.
This is done all the time to fit films to standard video resolution without using letterboxing. But just to be clear because so many people miss this: letterboxing is not cropping into or covering up the image. It’s the empty space left when fitting an entire wide image into a more square frame. So, it’s not about “removing” the letterboxing; it’s about zooming into the original image so it fits the whole screen top to bottom, sacrificing (removing) parts of the image composition on the sides.
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