youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/bestvideo+bestaudio' --merge-output-format mp4 'https://www.facebook.com/parisenselle/videos/481880002754292/' -o GrandOral_Live-Facebook_HD.mp4

Variante pour s'emmerder :
youtube-dl https://www.facebook.com/parisenselle/videos/481880002754292/ -F # list formats
youtube-dl https://www.facebook.com/parisenselle/videos/481880002754292/ -f 135306204242825ad -o audio.m4a  # get best audio
youtube-dl https://www.facebook.com/parisenselle/videos/481880002754292/ -f 848956452230464v -o video.mp4  # get best video
ffmpeg -i video.mp4 -i audio.m4a -c:v copy -c:a copy GrandOral_Live-Facebook_HD.mp4