I've seen some TV show SD clips and iPhone footage that have what looks like reflections on each side to "fill in the blanks" so to speak horizontally to make it look "HD-ish."
(Sorry if there's a tech term for this but this is the best way I could describe it.)
Thanks, but the problem is that the source file (that was "converted" to HD) has black "flaps" on either side and I can't figure out how to remove those so I can start with a true 4:3 clip. I can't seem to find any tutorials on how to crop a video the same way one might crop an image in Photoshop.
The cookie cutter plugin is the wrong tool. Instead, use pan/crop. You need to click on the match aspect button to turn it off. This switches the re-sizing tool into a crop tool. You then simply drag one of the handles on either side of the pan/crop box towards the center until you see the video itself start to get cropped, and then back off a little.