Phonon (KDE)

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Phonon

Phonon logo
Phonon settings
Phonon settings
Basic data

developer KDE
Current  version 4.10.2
(January 9, 2019)
operating system Unix-like ( e.g. FreeBSD , Linux , macOS ), S60 , Windows
programming language C ++ ( Qt )
category Multimedia framework
License LGPL
German speaking Yes
phonon.kde.org

Phonon (formerly provisionally also KDEMM ) is the Multimedia - API of KDE -Desktopumgebung. In addition, the Qt library from version 4.4 uses Phonon as a multimedia interface.

properties

Phonon offers developers of KDE / Qt software a uniform programming interface (API) for developing audio and video applications. In this respect it is comparable to the interfaces of DirectShow under Windows and QuickTime under macOS . Different back-ends are used while maintaining binary compatibility .

The background to this solution is that KDE programs since KDE 4.0 and Qt programs in general can also be run under Windows or Mac OS X, and multimedia solutions other than Linux are used there. In addition, several competing multimedia solutions are available under Linux itself ( GStreamer , xine , etc.). Phonon abstracts these problems and makes them irrelevant for developers of KDE software.

Phonon itself is not a sound server like aRts , which was still used under KDE 3.

history

The background to the development of Phonon were primarily technical and personnel problems at aRts. aRts was a promising solution to many of the audio problems under Linux that existed at the time in the beginning, but has not been developed enough over time to keep up with the development of computers towards more and more multimedia applications. As a result, after a few years various functions and options in aRts in the area of ​​audio support were missing, and video support was completely missing. aRts could not be replaced in KDE 3, as this would have violated binary compatibility.

After their experience with aRts, the developers came to the conclusion that it does not make sense to rely on a single project. Phonon was therefore developed as an adapter in order to be able to change the back end within the development line of KDE SC 4, if this should appear necessary, without having to adapt existing KDE applications. In addition, there was the problem that at the time the development of KDE SC 4 began, there was no uniform solution available under Linux: although the GStreamer project was favored by many, xine or MPlayer also offered themselves as comprehensive solutions.

Since other solutions such as the direct use of a specific back end (such as GStreamer) would also have required a wrapper to adapt them to the programming requirements of KDE, the Phonon solution only required a comparatively small amount of additional work compared to direct integration .

Initially, Phonon was primarily developed with the help of a Xine back-end. In December 2007 Trolltech contributed the support for the three backends GStreamer, QuickTime and DirectShow.

In mid-2009, the Qt developers, now taken over by Nokia, announced that they would develop a new framework called QtMultimedia instead of Phonon.

Supported back ends

Main back ends

Currently (April 2011) the Phonon developers are concentrating on the maintenance and further development of two back-ends: VLC and GStreamer .

The VLC back-end originally developed by Tanguy Krotoff has been considered stable since November 2010 and is recommended for use.

The GStreamer back-end may fail despite initial problems. a. Preferred by Linux distributors for reasons of storage space , as GStreamer is currently required by LibreOffice and the Qt version of WebKit anyway . However, it is only recommended for Linux as it has not been tested on any other platform.

More back ends

  • avKode : As part of the Google Summer of Code 2006, avKode was developed as a back-end based on FFmpeg . It is currently (January 2010) not further developed.
  • DirectShow : It was originally developed by Trolltech / Nokia and uses the old DirectShow -9 framework under Windows . Since the reorientation at Nokia in favor of QtMultimedia, it is no longer actively developed.
  • MMF : The "Multimedia Framework Architecture" (MMF) is the multimedia system for S60 .
  • NMM : This back-end uses the Network-Integrated Multimedia Middleware and is particularly geared towards media output via computer networks. It has not been further developed since January 2008.
  • Phonon-aRts : Phonon-aRts uses the aRts sound server known from KDE 3. It was planned that this should be supported by KDE 4 at least in the beginning to ensure compatibility with KDE 3 applications. However, it will not be further developed.
  • Phonon-Fake : Initially only intended to develop Phonon, this back-end does not provide any audio output.
  • Phonon-mplayer : This back-end uses the libraries of the MPlayer project. It was developed by Tanguy Krotoff.
  • QuickTime : It was originally developed by Trolltech / Nokia and uses the QuickTime -7 framework under macOS . Since the reorientation at Nokia in favor of QtMultimedia, it is no longer actively developed.
  • xine : Originally the standard back-end, but has not been further developed since 2010 and was officially marked as unsupported with the release of Phonon 4.4.4.

Web links

Individual evidence

  1. ↑ Release notes Phonon 4.10.2
  2. ↑ Trolltech and KDE Cooperate on Cross-Platform Multimedia Programming Framework  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. - Trolltech press release , December 13, 2007@1@ 2Template: Dead Link / qt.nokia.com  
  3. ↑ a b c Multimedia in Qt, what's the story? ( Memento of the original from November 27, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English) - Blog article at Nokia's Qt Labs , September 9, 2009 @1@ 2Template: Webachiv / IABot / labs.qt.nokia.com
  4. ↑ a b Announcement of Phonon 4.4.4 (January 21, 2011)
  5. ↑ Harald Sitter: Phonon-VLC 0.3 - Rock Solid (November 30, 2010)
  6. ↑ Harald Sitter: Kubuntu 04/11 Sneak Peak (December 3, 2010)
  7. ↑ Harald Sitter: "GStreamer always was a main Linux backend as no one ever tested it on other platform [s]." (Quoted from the developer mailing list of February 21, 2011. Source )
  8. ↑ Archived copy ( Memento of the original dated December 30, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. - former project page; As of January 13, 2008 @1@ 2Template: Webachiv / IABot / phonon.kde.org
  9. ↑ From the phonon website: Backend libraries (English) - forum post at the Chakra Project , August 3, 2010, quote: “Phonon-NMM: This is an abandoned and unmaintained backend started by the Graphics Lab at Saarland University and Motama. "