What is &fmt=22?
Normally, youtube videos are mono sound, and are low-res (320x180)
Adding &fmt=18 to the end of a youtube address will cause the video to be in higher quality (480x270), and will have stereo sound. This is the same as clicking "watch this video in high quality", and works in 99% of videos.
Adding &fmt=22 to the end of a youtube address will cause the video to be in HD (1280x720, aka 720p), and the audio is in stereo. This is not available in most videos. It is the same as clicking "Watch in HD"