Youtube-dl

https://github.com/rg3/youtube-dl/blob/master/README.md#readme

https://rg3.github.io/youtube-dl/download.html

https://github.com/rg3/youtube-dl/issues/4886#issuecomment-94792491  force mp4 highest res and best audio

example
youtube-dl --yes-playlist -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/mp4' 'https://www.youtube.com/watch?v=CaCcOwJPytQ&list=PLX2gX-ftPVXU3oUFNATxGXY90AULiqnWT' 

links
LinuxNotes