#EXTM3U
#PLAYLIST:Playlist title
#EXTINF:100, Artist - Title
/path/to/file.mp3
#EXTINF:[length_of_song_in_seconds], Artist - Title
/path/to/file.mp3

# apparently also m3u can just be a list
#EXTM3U
/path/to/song.mp3
/path/to/song.mp3
/path/to/song.mp3