How to Fix Aspect Ratio on already uploaded videos (CC available)

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If you have ever had black borders appear in your Youtube videos this video will show you how to get rid of them without having to reupload the entire thing

Original Youtube Blog post
youtube.com/blog?entry=Lsn9BnVuSAM

These lines of code are known by YouTube as Formatting Tags there are 4 available

yt:crop=16:9
(zooms in on the 16:9 area, removes windowboxing)

yt:stretch=16:9
(fixes anamorphic content by scaling to 16:9)

yt:stretch=4:3
(fixes 720x480 content that is the wrong aspect ratio by scaling to 4:3)

yt:quality=high
(default to a high quality stream,)

To use them simply copy and paste the code into the tags section of the video you want to fix

Here's some examples on youtube with using the code: (stretch 16:9)
youtube.com/watch?v=G-XViSEyYHA

(Zoom 16:9)
youtube.com/watch?v=PkEaYCkpEB8

NOTE a common problem I'm constantly asked about when using stretch=16:9 tag is that it sometimes doesn't stretch to remove the black bars and stretch the whole screen.

This is mainly because the video uploaded is in 16:9 widescreen ratio with black bars rendered into the video, the problem with this is that Youtube assumes the black bars are part of the video and doesn't stretch beyond the dimensions of the video with this tag, that only applies with the crop tag but not the stretch tag