A playlist or playlist (from English playlist ) is a list of audio or video files in a defined playback order. Today, playlists mainly refer to the compilation of digital pieces of music (see also MP3 ) that are played on computers .
In contrast to container formats , playlists only contain addresses of content that they control playback. Container formats encapsulate this content within a stream or a file.
Playlists are used by streaming services such as Icecast or Microsoft's ASX to increase availability, distribute load or assign personalized streams. Apple's HTTP Live Streaming Protocol (HLS) uses M3U playlists to segment the video output.
Originally the term was used in radio and describes the listing of precisely certain pieces of music that are to be played and were played during a broadcast . Today, many commercial radio and music TV broadcasters use a “ rotation principle ”. The playlists are automatically selected from a “pool” of given pieces of music using a random generator . This pool is maintained by a music editor who determines which title appears in the program and how often, and possibly also provides the individual title entries with additional meta information, for example to prevent titles from the same artist from being played one after the other in different music projects (for Example, no Genesis title should be played after a Phil Collins title ).
Playlists are based on the program format of a station and only take into account those pieces of music that fit the format, i.e. H. an oldie station only records " oldies ". The lists are usually revised weekly. They contain 8 to 25 "A-songs", which are preferred because of their popularity (see Airplay ), and the rest, which are usually only played once. Playlists are used to implement the station format and as a basis for accounting with the responsible music collecting society (e.g. GEMA ). Such playlists are also used in music television broadcasters .
In playlists the order is scheduled to be played in certain titles.
All common playback programs ( audio players ), such as Winamp for Microsoft Windows or Amarok for Linux , support playlists .
The playlists can also be saved here.
- ASX : from Microsoft, similar to SMIL , is mostly used as a “streaming playlist”.
- M3U : common, plain text based
- PLS : common, plain text based
- RSS is used as a playlist for audio content in podcasts .
- WPL : less common, based on XML .
- XSPF : less common, based on XML, can also store some metadata .
Differences between M3U and PLS
One advantage of M3U (compared to PLS) is that relative path specifications are possible. There is no longer any difference between Win and UNIX / Linux, and the lists are portable.
It should be mentioned that the choice / decision between M3U or PLS has no influence on the sound quality of the music.
In addition to the static playlists, there are also dynamic playlists (e.g. "Smart Playlists" in iTunes ) which automatically select pieces of music from a specified collection according to defined criteria when they are called up. There is no need to manually add individual pieces. Such a dynamic playlist could be defined as follows: “Show from those pieces of music that I have rated with five stars, the 50 that have not been heard for the longest”. This is also known as a "smart playlist". If an automatic update is active, in this example a played piece of music automatically disappears from the list (since it no longer fulfills the criterion “the longest not played” afterwards), and another one slides down, so that the list reaches the 50th at any point in time currently contains five-star music tracks that have not been played for the longest time.