youtube-dl

# automatically download to $HOME/vid/stream
-o ~/vid/stream/"%(autonumber)d - %(title)s.%(ext)s"

# always get free formats if available
--prefer-free-formats

# default to bestvideo+bestaudio
-f ((bestvideo[ext=webm]/bestvideo)+(bestaudio))/best

# auto-merge to mkv
--merge-output-format mkv

# get best-quality subtitles and embed them
--sub-format best
--all-subs
--embed-subs

# default to not downloading playlists
--no-playlist