M3U playlists are "old school" playlists, which were originally implemented by Winamp. An M3U file is a plain text file that contains the locations of one or more media files that the media player should play. Each location is placed on a new line.
This option does not require any kind of special server-side functionality and is similar in nature to an XML playlist. The main difference between an XML playlist and an M3U playlist is that an XML playlist allows you to provide much more information about a track. Whereas M3U playlists only allow you to include total seconds and track title.
Here is an example of an M3U playlist. Explanations are color coded below:
#EXTINF:342,My Cool Song One
#EXTINF:301,Another Track Title
The exact string of "#EXTM3U" is used to define the text file as an M3U playlist
The exact string of "#EXTINF:" indicates that new track information follows.
Following the colon is a number representing the total number of seconds for the track
Following the comma after the seconds is the title of the track
URL to file
The line below the track data line refers to the URL for the file. This can be either a relative or absolute URL. We highly recommend using absolute URLs. Click here for more information on "relative and absolute"
To use an M3U playlist
Use the Customizer Tool and click on the "Media" tab to open it. Choose "M3U or PLS " from the drop-down selector.
Enter the URL to the playlist file on your web site.