Here is the list of all the websites this application supports NOT JUST YOUTUBE!
We analyze the code in the terminal with youtube-dl –help.
Audio + Video
youtube-dl -f bestvideo+bestaudio https://www.youtube.com/watch?v=f_tH3qARp0U
youtube-dl -x --audio-format mp3 https://www.youtube.com/watch?v=f_tH3qARp0U
You will get a video and an mp3 to play with any player of your choice.
The audio format can be in mp3 but also best, aac, flac, m4a, opus, vorbis, wav.
If we use best for this link, we will get opus. Others came in with ogg. So the source matters when you use best.
Many formats are possible