https://github.com/rg3/youtube-dl#format-selection-examples
youtube-dl --yes-playlist -f 'best[ext=mp4]' https://www.youtube.com/playlist\?list\=XXX
https://github.com/rg3/youtube-dl#format-selection-examples
youtube-dl --yes-playlist -f 'best[ext=mp4]' https://www.youtube.com/playlist\?list\=XXX