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M3U

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M3U
Filename extensions
.m3u, .m3u8
Internet media typevarious; see § Internet media types
Initial releasec. 1996
Type of formatPlaylist
Extended toHTTP Live Streaming playlist

M3U (MP3 URL[1][2] or Moving Picture Experts Group Audio Layer 3 Uniform Resource Locator[3] in full) is a computer file format for a multimedia playlist. One common use of the M3U file format is creating a single-entry playlist file pointing to a stream on the Internet. The created file provides easy access to that stream and is often used in downloads from a website, for emailing, and for listening to Internet radio.

Although originally designed for audio files, such as MP3, it is commonly used to point media players to audio and video sources, including online sources. M3U was originally developed by Fraunhofer for use with their WinPlay3 software,[4] but numerous media players and software applications now support the format.

Careless handling of M3U playlists has been the cause of vulnerabilities in many music players such as VLC media player,[5] iTunes,[6] Winamp,[7] and many others.[8]

File format

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There is no formal specification for the M3U format; it is a de facto standard.

An M3U file is a plain text file that specifies the locations of one or more media files. The file is saved with the "m3u" filename extension if the text is encoded in the local system's default non-Unicode encoding (e.g., a Windows codepage), or with the "m3u8" extension if the text is UTF-8 encoded.[9]

Each entry carries one specification. The specification can be any one of the following:

  • an absolute local pathname; e.g., C:\My Music\Heavysets.mp3
  • a local pathname relative to the M3U file location; e.g. Heavysets.mp3
  • a URL

Each entry ends with a line break which separates it from the following one. Furthermore, some devices only accept line breaks represented as CR LF, but do not recognize a single LF.

Extended M3U

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The M3U file can also include comments, prefaced by the "#" character. In extended M3U, "#" also introduces extended M3U directives which are terminated by a colon ":" if they support parameters.

M3U extensions
Directive Description Example Required Standard
#EXTM3U file header, must be the first line of the file #EXTM3U 1× Yes
#EXTINF: track information: runtime in seconds then optional display title of the following resource #EXTINF:123,Artist Name – Track Title No Yes
additional properties as key-value pairs #EXTINF:123 logo="cover.jpg",Track Title No IPTV
#PLAYLIST: playlist display title #PLAYLIST:Music TV 1× IPTV
#EXTGRP: begin named grouping #EXTGRP:Foreign Channels No IPTV
#EXTALB: album information, title in particular #EXTALB:Album Title (2009) 1× AL,[10] M3A[11]
#EXTART: album artist #EXTART:Various 1× AL,[10] M3A[11]
#EXTGENRE: album genre #EXTGENRE:Jazz Fusion 1× AL[10]
#EXTM3A playlist for tracks or chapters of an album in a single file #EXTM3A 1× M3A[11]
#EXTBYT: file size in bytes #EXTBYT:34124 No M3A[11]
#EXTBIN: binary data follows, usually concatenated MP3s #EXTBIN: No M3A[11]
#EXTENC: text encoding, must be the second line of the file #EXTENC:UTF-8 1× No
#EXTIMG: cover, logo or other image #EXTIMG:cover.jpg No No

Apple used the extended M3U format as a base for their HTTP Live Streaming (HLS)[12] which was documented in an Independent Submission Stream RFC in 2017 as RFC 8216.[13] Therein, a master playlist references segment playlists which usually contain URLs for short parts of the media stream. Some tags only apply to the former type and some only to the latter type of playlist, but they all begin with #EXT-X-.

HLS M3U extensions
Directive Example Description
#EXT-X-START: TIME-OFFSET=0
#EXT-X-INDEPENDENT-SEGMENTS Toggle without parameters
#EXT-X-PLAYLIST-TYPE: VOD or EVENT
#EXT-X-TARGETDURATION: 10 The maximum Media Segment duration in seconds
#EXT-X-VERSION: 4
#EXT-X-MEDIA-SEQUENCE: 0 The Media Sequence Number of the first Media Segment appearing in the playlist file
#EXT-X-MEDIA: NAME="English", TYPE=AUDIO, GROUP-ID="audio-stereo-64", LANGUAGE="en", DEFAULT=YES, AUTOSELECT=YES, URI="english.m3u8"
#EXT-X-STREAM-INF: BANDWIDTH=1123000, CODECS="avc1.64001f,mp4a.40.2" Parameters have either one combined value or one per stream, separated by commas
#EXT-X-BYTERANGE: 1024@256000
#EXT-X-DISCONTINUITY toggle without parameters The segment represents the start of a new period
#EXT-X-DISCONTINUITY-SEQUENCE: 2 Indicates start of numbering of periods
#EXT-X-GAP toggle without parameters The segment represents a "spacer" before a new period
#EXT-X-KEY: METHOD=NONE Indicates encryption method used and decryption key
#EXT-X-MAP: URI=MediaInitializationSection
#EXT-X-PROGRAM-DATE-TIME: 2010-02-19T14:54:23.031+08:00 ISO 8601 format
#EXT-X-DATERANGE: ID=foo
#EXT-X-I-FRAMES-ONLY i-frame Toggle without parameters
#EXT-X-SESSION-DATA: DATA-ID=com.example.movie.title
#EXT-X-SESSION-KEY:
#EXT-X-ENDLIST End-of-list signal without parameters

M3U8

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The Unicode version of M3U is M3U8, which uses UTF-8-encoded characters. M3U8 files are the basis for the HTTP Live Streaming (HLS) format originally developed by Apple to stream video and radio to iOS devices, and which is now a popular format for adaptive streaming in general.

The 2015 proposal for the HLS playlist format uses UTF-8 exclusively and does not distinguish between the "m3u" and "m3u8" file name extensions.[14]

Internet media types

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The only Internet media type registered for M3U and M3U8 is application/vnd.apple.mpegurl, registered in 2009 and only referring to the playlist format as used in HLS applications.[15][16]

The current proposal for the HLS playlist format acknowledges two media types which it treats as equivalent: application/vnd.apple.mpegurl and audio/mpegurl.[14] Likewise, these are the two types recommended for HLS use by Microsoft.[17]

For non-HLS applications, no media types were standardized or registered with the IANA, but a number of media types are nonetheless associated with the historical and ongoing use of the M3U and M3U8 formats for general playlists:

  • application/mpegurl
  • application/x-mpegurl
  • audio/mpegurl
  • audio/x-mpegurl[1][2]

These types, plus application/vnd.apple.mpegurl and application/vnd.apple.mpegurl.audio, are supported for HLS applications by (for example) Microsoft's Windows 10[17] and Internet Explorer 9,[18] and LG's WebOS.[19]

Examples

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Example 1

This is an example of an extended M3U file on the Windows platform. Sample.mp3 and Example.ogg are the media files. 123 and 321 are the lengths in seconds.[20] A length of -1 or 0 may be used when the media file is a streaming file, as there is no actual, predefined length value. The value after the length is the title to be shown, which is generally the same as the location of the file which is on the second line. On the macOS and Linux platforms, Unix paths are used. 

#EXTM3U
 
#EXTINF:123, Sample artist - Sample title
C:\Documents and Settings\I\My Music\Sample.mp3
 
#EXTINF:321,Example Artist - Example title
C:\Documents and Settings\I\My Music\Greatest Hits\Example.ogg
Example 2

This example shows how to create an m3u file linking to a specified directory (for example, a flash drive, or CD-ROM). The m3u file should contain only one string: the path to the directory. After starting, the media player will play all contents of the directory: 

C:\Music
Example 3

Here is another example, using relative format. The M3U file is placed in the same directory as the music, and directories must be preserved when moving the playlist to another device if subdirectories are used. This method is more flexible, as it does not rely on the file path staying the same.

This is the same file as above, saved as sample.m3u in C:\Documents and Settings\User\My Music\ 

#EXTM3U
 
#EXTINF:123, Sample artist - Sample title
Sample.mp3
 
#EXTINF:321,Example Artist - Example title
Greatest Hits\Example.ogg

This format in an M3U allows copying to another device for playback. All files and directories referred to must also be copied.

Example 4

Here is a mixed example: 

Alternative\Band - Song.mp3
Classical\Other Band - New Song.mp3
Stuff.mp3
D:\More Music\Foo.mp3
..\Other Music\Bar.mp3
http://www.example.com:8000/Listen.mp3
http://www.example.com/~user/Mine.mp3

Notes:

  • Alternative and Classical are sub-directories of the directory that this playlist is stored in.
  • "Song" and "New Song" are in sub-directories of the directory that this playlist is stored in.
  • "Stuff" is in the same directory that the playlist is stored in.
  • "Foo" is in the specified (Windows) volume and directory, which may or may not be the same directory the playlist is in.
  • "Bar" is in a different directory at the same level as the playlist directory. The double-dots reference the parent directory of the playlist directory, then into the sub-directory "Other Music" to reach "Bar".
  • "Listen" is a Shoutcast stream.
  • "Mine" is an MP3 stored on a web server.
Example 5

References to other M3U playlists, for example, are generally not well-supported. 

AnotherPlayList.m3u
Example 6

The following is an example of a M3U playlist file for "Jar of Flies" album by "Alice in Chains" that was created by Mp3tag with the following custom option settings:[21][22][23]

  • playlist extended info format = "%artist% - %title%"
  • playlist filename format = "%artist%_%album%_00_Playlist.m3u"
  • tag to filename conversion format = "%artist%_%album%_$num(%track%,2)_%title%"
 #EXTM3U
 #EXTINF:419,Alice in Chains - Rotten Apple
 Alice in Chains_Jar of Flies_01_Rotten Apple.mp3
 #EXTINF:260,Alice in Chains - Nutshell
 Alice in Chains_Jar of Flies_02_Nutshell.mp3
 #EXTINF:255,Alice in Chains - I Stay Away
 Alice in Chains_Jar of Flies_03_I Stay Away.mp3
 #EXTINF:256,Alice in Chains - No Excuses
 Alice in Chains_Jar of Flies_04_No Excuses.mp3
 #EXTINF:157,Alice in Chains - Whale And Wasp
 Alice in Chains_Jar of Flies_05_Whale And Wasp.mp3
 #EXTINF:263,Alice in Chains - Don't Follow
 Alice in Chains_Jar of Flies_06_Don't Follow.mp3
 #EXTINF:245,Alice in Chains - Swing On This
 Alice in Chains_Jar of Flies_07_Swing On This.mp3

Software

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Tag editors

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See also: Category:Tag editors

The following tag editor software allows users to edit the ID3 tags in MP3 files, and has support for creating M3U files.

Linux
Windows

Media players

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See also: Category:Media players

The following media player software supports playing M3U files.

Multi-platform
Programs Platforms
Windows macOS Linux Android Other
Amarok Yes No Yes No No
Audacious Yes No Yes No No
Banshee Yes Yes Yes No Yes
Clementine Yes Yes Yes No Yes
GNOME Videos No No Yes No No
Kodi Yes Yes Yes Yes Yes
MOC (Music on Console) No No Yes No Yes
MPlayer Yes Yes Yes Yes Yes
mpv Yes Yes Yes Yes Yes
VLC media player Yes Yes Yes Yes Yes
iTunes Yes Yes No No No
Android
macOS
Nintendo
Windows

See also

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Other playlist file formats
  • ASX - Windows media
  • PLS - SHOUTcast
  • XSPF - Xiph.Org Foundation
  • WPL - Windows Media Player

References

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  1. ^ a b Fraunhofer Gesellschaft, Fraunhofer Institut für Integrierte Schaltungen-A (1996-10-30). "WinPlay3 - Windows real-time ISO/MPEG Audio Layer 3 Player". Archived from the original on 1997-06-06. Retrieved 2018-01-21.
  2. ^ a b Gruett, Matt. "M3U FILES AND STREAMING". LockerGnome. Archived from the original on 2001-04-26.
  3. ^ Nero. "Nero MediaHome 4 - Manual" (PDF). Archived (PDF) from the original on 2015-09-05.
  4. ^ "WINAMP.COM | Winamp Documentation". June 6, 2002. Archived from the original on 2002-06-06.
  5. ^ "VideoLAN-SA-0804 (CVE-2007-6683)". 2008. Arbitrary file overwrite and other abuses through M3U parser and browsers plugins.
  6. ^ "CVE-2012-0677: Heap-based buffer overflow in Apple iTunes before 10.6.3 allows remote attackers to execute arbitrary commands". cve.circl.lu.
  7. ^ "CVE-2000-0624: Buffer overflow in Winamp 2.64 and earlier allows remote attackers to execute arbitrary commands via a long #EXTINF: ext". www.cvedetails.com.
  8. ^ "247 search results". Packet Storm. Retrieved 2018-01-23.
  9. ^ "Nero 2015 Platinum - System Requirements". MP3 URL + UTF-8 (M3U8)
  10. ^ a b c "Album List for Winamp". albumlist.sourceforge.net.
  11. ^ a b c d e "Data". birdcagesoft. Retrieved 2019-10-21.
  12. ^ "About the Common Media Application Format with HTTP Live Streaming | Apple Developer Documentation". developer.apple.com.
  13. ^ R. Pantos and W. May (August 2007). HTTP Live Streaming. RFC Editor. sec. 4.3. doi:10.17487/RFC8216. ISSN 2070-1721. RFC 8216.
  14. ^ a b Pantos, Roger; May, William. "HTTP Live Streaming". tools.ietf.org.
  15. ^ "Media Types". www.iana.org.
  16. ^ "Data". iana. Retrieved 2019-10-21.
  17. ^ a b "Simplified Adaptive Video Streaming: Announcing support for HLS and DASH in Windows 10 – IEBlog". blogs.msdn.microsoft.com.
  18. ^ "HTMLVideoElement". MDN Web Docs.
  19. ^ "::: LG Developer | Audio & Video :::". Archived from the original on 2015-12-22. Retrieved 2015-12-12.
  20. ^ "DigiLinX Application Note - Creating Playlists to Work with the Streaming Music Manager" (PDF). 2007-10-05.
  21. ^ "Mp3tag Help - Configuration > Export". help.mp3tag.de.
  22. ^ "Mp3tag Help - Configuration > Playlist". help.mp3tag.de.
  23. ^ "Mp3tag Help - Scripting functions". help.mp3tag.de.
  24. ^ "Loading..." astroplayer.com. Archived from the original on December 1, 2009.
  25. ^ "Astro Player (old) - Sidenis LLC". Archived from the original on March 3, 2016.
  26. ^ "Astro Player - Sidenis LLC". Archived from the original on March 3, 2016.
  27. ^ "n7player Music Player - Apps on Google Play". play.google.com.
  28. ^ "n7player 1.0 - Apps on Google Play". play.google.com.
  29. ^ "Musicolet Music Player [No ads] - Apps on Google Play". play.google.com. Retrieved 2020-11-02.
  30. ^ Hindley, Nathan. "XMPlay 3.8.2". XMPlay. Un4seen Developments. Retrieved 11 July 2016.
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