Simply add a code or two to the tags section of your YouTube video to change how it plays.
You can adjust the dimensions of your video by either cropping or stretching…
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 720×480 content that is the wrong aspect ratio by scaling to 4:3)
Or ensure that your video defaults to high quality (where available).
yt:quality=high(default to a high quality stream, depending on availability)
