Revision 730076405 of "XMMS2" on enwiki

{{Distinguish|XMMS}}
{{Infobox software
| name = XMMS2
| logo = [[Image:XMMS2-Logo-white-128.png]]
| screenshot =
| caption =
| author =
| developer = XMMS Team
| released =
| latest release version = 0.8 DrO+WIP<ref>
| latest release date = {{start_date_and_age|2011|10|20}}[https://bugs.xmms2.org/changelog_page.php Change Log]</ref>
| latest preview version = 0.9 DrP
| latest preview date = 
| operating system =  [[Unix-like]]
| platform =
| language = [[C (programming language)|C]]<ref>[https://xmms2.org/wiki/XMMS2_vs_MPD#Main_plans XMMS2 vs MPD]</ref>
| status =
| genre = [[List of free software for audio#Players|Audio player]]
| license = [[GNU General Public License|GPL v2]] / [[GNU Lesser General Public License|LGPL v2.1]] (plugins)
| website = [http://www.xmms2.org/ www.xmms2.org]
}}
'''XMMS2''' ('''''X'''-platform '''M'''usic '''M'''ultiplexing '''S'''ystem '''2''''') is a new generation of the [[XMMS]] audio player. It is a new design, written from scratch, separate from the [[XMMS]] codebase. While Peter Alm, one of the original authors of XMMS, was responsible for the initial design and coding of XMMS2 (late 2002 to early 2003),<ref>[http://wiki.xmms2.xmms.se/index.php/History/Ancient#.28Late_2002.29 Project history] {{wayback|url=http://wiki.xmms2.xmms.se/index.php/History/Ancient#.28Late_2002.29 |date=20061011034123 }}, XMMS2 Project, retrieved January 11, 2007</ref> he has since passed on the responsibility of furthering the project to Tobias Rundström and Anders Gustafsson.<ref>[http://wiki.xmms2.xmms.se/index.php/About/People#Lead_Developers Lead Developers] {{wayback|url=http://wiki.xmms2.xmms.se/index.php/About/People#Lead_Developers |date=20070102053923 }}, XMMS2 Project, retrieved January 11, 2007</ref> LXMusic, the default music player application in [[LXDE]], is an XMMS2 client.

==Design concepts==
XMMS2 borrows concepts from XMMS-era music players, such as playback control, a [[playlist]], [[Plug-in (computing)|plugin]]s, user-configurable [[GUI]], and adds features such as a media library and a [[client–server]] design.

Like XMMS, XMMS2 has a [[Plug-in (computing)|plugin]] architecture; a type of modular architecture where certain functions are delegated to loadable [[Library (computing)|libraries]] which provide particular functions at [[Run time (program lifecycle phase)|run-time]]. XMMS recognised five different types of plugins:
* Input plugins for reading and decoding files or streams.
* Output plugins to handle sound output.
* Effects plugins to add effects to decoded audio data, before being output.
* Visualisation plugins to provide visual animations that vary according to the audio being played.
* General plugins which allow for miscellaneous functions such as controlling XMMS via an Infrared remote control or a Joystick.
''XMMS2'' also recognises five types of plugins, but they perform rather different functions:
* Transport plugins for reading files or streams.
* Decoder plugins for decoding data read by transport plugins.
* Effect plugins to add effects to decoded audio data, before being output.
* Output plugins to handle sound output.
* Playlist plugins to handle the importing and exporting of playlist data.

Unlike XMMS2, XMMS had no library where it stored information about a user's media collection. The only media resources XMMS knew about were its playlist. Starting in around 2000, players like [[Winamp]] and [[SoundJam MP]] began implementing simple [[database]] features that allow the player to "remember" where a user's media is located, as well as caching [[metadata]] stored in the files such as artist, title, date added and play count.

XMMS2's media library is well integrated with the playlist. This integration means that every file or stream added to the playlist has its metadata automatically cached by  the media library. This only happens once for every unique URL, so metadata isn't read again if it already exists in the library. Besides metadata, the media library can also quickly and efficiently store and reload playlists, making a user's music collection all accessible from a single place.

One feature of XMMS2 that has been rarely implemented in media players is its client-server architecture. XMMS2 allows the user to choose from a number of interface implementations for searching, selecting and playing media, then to close the interface while the audio plays "in the background". The interface can be reopened at any time for further use. Other players with similar features on *nix include the [[Music Player Daemon]] and [[Music on Console]].

===The design===
When first conceived, XMMS2 was simply a [[shared library]]. That is, XMMS2 would be [[Front and back ends|back end code]] to take care of the mechanics of decoding and playing audio streams, requiring to be [[linking (computing)|linked]] into a compiled program that provided a user interface. This concept was later expanded into a client–server model to allow for more flexible coupling between the front-end and the back-end.<ref>[http://wiki.xmms2.xmms.se/index.php/Design_of_XMMS2 Design of XMMS2] {{wayback|url=http://wiki.xmms2.xmms.se/index.php/Design_of_XMMS2 |date=20051027174726 }}, XMMS2 Project, retrieved January 11, 2007</ref> The advantages of this approach are:
* This allows any compatible client(s) to connect to and control a single instance of the XMMS2 [[Daemon (computer software)|daemon]].
** Clients can offer various types of user interfaces&nbsp;– graphical or text based, implemented using various toolkits, integrated with various [[desktop environment]]s.
** Client developers can concentrate on improving the usability of their interface, and not worry about playback code.
* The use of TCP sockets also allows for users to remotely control XMMS2 daemons over a TCP/IP network.

While the plugin architecture of XMMS allowed it to be quite extensible, it was inefficient in certain ways; XMMS2 seeks to improve on that.
* XMMS has Input plugins that take care of reading data and decoding it to audio. XMMS2 splits this into a Transport stage and a Decode stage, so that a single transport plugin may supply data of any type to any decoder plugin (such as an HTTP plugin reading mp3 data from a web site).
* General plugins may prove to be less relevant in XMMS2, as their purpose may be served by standalone clients, but the plugin architecture will still exist.
* XMMS can't handle container formats in a general manner. The XMMS2 architecture makes it easier to build support for container formats.

==XMMS2 and other projects==
The name "XMMS2" was chosen by Peter Alm and Tobias Rundström as they started work on the project, evidently intending it to become the successor to XMMS. However, other developers started using the name (in 2003) before Peter and Tobias ever released their code:

* Another project named XMMS2, by Mohammed Sameer, was described as "a Gtk 2 port of the well known xmms." This was not related to the project discussed in the rest of this article. The project has now been discontinued and removed from [[GNU Savannah]].
* A better known [[GTK+|GTK+ 2]] port of XMMS is the [[Beep Media Player]], which is sometimes referred to (erroneously) as XMMS2.<ref>[http://www.advogato.org/person/fatal/#2 'Another one.'] by [http://www.advogato.org/person/fatal/ Thomas Nilsson], 2003-11-08, retrieved January 11, 2007</ref> The [http://bmp.backtrace.info/index.php?title=FAQ BMP FAQ] explains that project's relationship to XMMS.

A subtle difference between the ''XMMS'' and ''XMMS2'' acronyms is that, while XMMS stands for ''X (originally for X11 then Cross-platform) MultiMedia System'', XMMS2 stands for ''X(Cross-platform) music multiplexing system''. This decision was made to make it clear that XMMS2 would only ever be an audio player, and not a general multimedia player with video support.

{{Portal|Free software}}

==References==
{{Reflist}}

==External links==
* [http://www.xmms2.org/ XMMS2 homepage]

{{GTK}}
{{Media player (application software)|free}}

{{DEFAULTSORT:Xmms2}}
[[Category:Audio player software that uses GTK+]]
[[Category:Beta software]]
[[Category:Client/server media players]]
[[Category:Free audio software]]
[[Category:Free media players]]
[[Category:Free software programmed in C]]
[[Category:Linux media players]]