A while back I uploaded a bunch of Youtube videos in 16:9 format and found they did not display correctly. They had the black bars at the top and bottom despite being viewed in 720p which is a 16:9 format. Eventually I found out I could fix this by one of two ways, one was not to upload directly through my video editing software and the other was by adding a tag that said yt:crop=16:9. This was a hidden tag but was used by the Youtube video player to adjust the video to that screen format. It worked and I used it and forgot about it, until now.
Today a subscriber let me know my videos were all zoomed in about 20% and a lot of my titles were chopped off as a result. It also really amplified any shakiness making it look it was filmed by Michael J Fox. I figure Youtube must have changed something on their site, as nothing seemed to prompt this on my end. I’ve had a few other videos get messed up when I had edited them using their in browser editor, but in this case I had not done so. Eventually I noticed it was just the videos that were using that tag and thus I removed them, which fixed the new issue but gave me back my original one. So after a bit of research I ended up back at this page which mentioned another stretch option. I did not remember this one being there before but either way it did not sound like what I wanted, but I tested it anyways. Alas, that was the solution! All you have to do is change yt:crop=16:9 to yt:stretch=16:9.
Youtube must have changed the way these worked and not told anyone. Thanks Youtube.