Playlist Formats
Here some playlist files that you can see on internet radios
A resource address can be anything the M3U reader is capable of understanding. These include absolute filesystem paths, relative filesystem paths (with the base undefined by the file format), and URLs. A resource can be anything the M3U reader is capable of rendering. To my knowledge these are always audio files, but there is no set reason for that to be true. However, it may not be wise to point to proprietary media formats like Real streaming audio in an M3U file, since many players will throw a user-visible error for media they cannot render. The design philosophy of M3U is to let resource data types do the work. Players that don't understand an address or resource type usually skip the entry. The ability to reference URLs, in addition to filesystem paths, was added this way; some players (Winamp and XMMS, notably) simply added the ability to handle URLs to their M3U readers. Support for M3U features varies wildly. iTunes, for example, will only render the first entry in an M3U file. M3U is by far the most popular playlist format, probably due to its simplicity. It is an ad-hoc standard with no formal definition, no canonical source, and no owner. The First line, "#EXTM3U" is the format descriptor, in this case M3U (or Extended M3U as it can be called). It does not change, it's always this. The second and third operate in a pair. The second begins "#EXTINF:" which serves as the record marker. The "#EXTINF" is unchanging. After the colon is a number: this number is the length of the track in whole seconds (not minutes:seconds or anything else. Then comes a comma and the name of the tune (not the FILE NAME). A good list generator will suck this data from the ID3 tag if there is one, and if not it will take the file name with the extension chopped off. The second line of this pair (the third line) is the actual file name of the media in question. In my example they aren't fully qualified because I run this list by typing "noatun foo.m3u" in my home directory and my music is in ~/mp3, so it just follows the paths as relative from the path of invocation. The ASX family of formats are somewhat a moving target, however, since they are defined by implementation in the windows Media Player and related APIs, which is changing rapidly at this time. I suspect but haven't confirmed that just about any kind of media can be pointed to within a playlist as long as the playlist is correctly handed off from the browser to Windows Media Player.
M3U
Description:
Every line in an M3U file is either a comment, a blank, or a resource to render.
A comment line begins with the pound sign, #.
Blanks are ignored. A resource is the address of a media file.
Example:
# This is an absolute filesystem path
c:/music/foo.mp3
# This is a relative filesystem path
foo/fighters.mp3
# This is a URL
http://foofighters.com/somesong.mp3
Mime type:
audio/mpegurl (recommended)
audio/x-mpegurl
Distinguishing features:
A simple list of files, one per line.
Definition URL:
http://www.schworak.com/programming/music/playlist_m3u.asp
Originator:
Winamp (?)
Implementations:
Winamp, XMMS, many more
Metadata support:
Before ID3 tags were widely supported by MP3 players, a flavor of M3U called Extended M3U was used to indicate audio metadata.
Extended M3U is now obsolete.
The following description of Extended M3U is copied in verbatim from Google's cache of the reverse-engineered documentation athttp://hanna.pyxidis.org/tech/m3u.html which is now a defunct URL.
#EXTM3U
#EXTINF:111,3rd Bass - Al z A-B-Cee z
mp3/3rd Bass/3rd bass - Al z A-B-Cee z.mp3
#EXTINF:462,Apoptygma Berzerk - Kathy«s song (VNV Nation rmx)
mp3/Apoptygma Berzerk/Apoptygma Berzerk - Kathy's Song (Victoria Mix by VNV Nation).mp3
#EXTINF:394,Apoptygma Berzerk - Kathy's Song
mp3/Apoptygma Berzerk/Apoptygma Berzerk - Kathy's Song.mp3
#EXTINF:307,Apoptygma Bezerk - Starsign
mp3/Apoptygma Berzerk/Apoptygma Berzerk - Starsign.mp3
#EXTINF:282,Various_Artists - Butthole Surfers: They Came In
mp3/Butthole_Surfers-They_Came_In.mp3
ASX
Description:
One of the three Windows Media metafile formats. The three are ASX, WAX, and WVX.
These formats are identical except for the type of content they may point to. ASX may only point to .asf content.
Example:
Microsoft Corporation
(c)2003 Microsoft Corporation
Mime type:
video/x-ms-asf (also used for .asf files)
Distinguishing features:
Can point to .asf files ONLY.
Definition URL:
Originator:
Microsoft
Implementations:
Various Microsoft media players
Metadata support:
Predefined fields related to entries including author, title, and copyright information.
WAX
Description:
Exactly like ASX and WVX, except that it can only contain references to .asf or .wma, but NOT to .wmv files. See ASX reference for more details.
Example:
Microsoft Corporation
(c)2003 Microsoft Corporation
Microsoft Corporation
(c)2003 Microsoft Corporation
Mime type:
audio/x-ms-wax
Distinguishing features:
Can only contain references to .asf or .wma files.
Definition URL:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmplay/mmp_sdk/creatingmetafileplaylists.asp
Originator:
Microsoft
Implementations:
Various Microsoft media players
Metadata support:
Predefined fields related to entries including author, title, and copyright information.
