M3U playlists are just a text file containing links to the location of the proper file. You can crate or edit a playlist in any text editor. It could be anything to MP3, WMA, or even another playlist. Just because something is in a playlist, doesn't mean Winamp can play it though. Winamp will just skip over unknown file formats. This document will hopefully toy to clarify the differences of the playlist formats available.
Generic M3U file
A list of links to files makes a valid generic playlist. The entry can be relative (i.e. \files\song.mp3) or specific (i.e. c:\media\files\son.mp3). Also, URLs can he inserted to point to a stream or a file on the Internet.
Here are a few sample generic MP3/PLS files:
Alternative\Song.mp3 Classical\New_Song.mp3 crap.mp3 F:\more music\foo_bar.mp3 http://www.site.com:8000/listen.pls http://www.site.com/~user/mine.mp3
These path options hold true of the extended playlists described below.
Let's first look at an extended M3U file then I will describe everything below
#EXTM3U #EXTINF:233,Everclear - So Much For The Afterglow Alternative\everclear_SMFTA.mp3 #EXTINF:227,Weird Al - Everything You Know Is Wrong Comedy\Weird_Al_Everything_You_Know_Is_Wrong.mp3 #EXTINF:187,Weird Al Yankovic - This is the Life Weird_Al_This_Is_The_Life.mp3 #EXTINF:129,Weird Al: Bad Hair Day - Gump http://www.site.com/~user/gump.mp3 #EXTINF:-1,My Cool Stream http://www.site.com:8000/listen.pls