/**
\page phonon_Backend The Backend Class
\ingroup Backend

\section phonon_Backend_requiredfunctions Required Functions
\li bool \ref phonon_Backend_supportsOSD "supportsOSD()"
\li bool \ref phonon_Backend_supportsFourcc "supportsFourcc( quint32 )"
\li bool \ref phonon_Backend_supportsSubtitles "supportsSubtitles()"
\li bool \ref phonon_Backend_supportsVideo "supportsVideo()"
\li QStringList \ref phonon_Backend_availableMimeTypes "availableMimeTypes()"

\section Member Function Documentation

\subsection phonon_Backend_supportsFourcc bool supportsFourcc( quint32 fourcc )
Tells whether the FOURCC (four character code) is supported for
the \ref phonon_VideoDataOutput "VideoDataOutput" interface. If you return \c true, you have to be
able to return VideoFrame objects accordingly from
\ref phonon_VideoDataOutput "VideoDataOutput".
\param fourcc A four character code defining a video frame format.
\returns \c true if your \ref phonon_VideoDataOutput "VideoDataOutput" can
output video frames in the requested format.
\returns \c false if the video frames can not be converted into the requested
format.

\subsection phonon_Backend_availableMimeTypes QStringList availableMimeTypes()
Lists the MIME types the backend can read and decode.

\subsection phonon_Backend_xIndexes QSet<int> <device/codec/effect/...>Indexes()
	Returns a set of indexes that identify the devices/codecs/effects/... the
	backend supports. This list needs to be compiled from looking at
	available hardware and virtual devices/plugins/... . The implementation
	should use cached information, but you need to invalidate the cache
	whenever the hardware configuration changes or new virtual devices come
	available/new plugins are installed/... .

	\return The indexes of the available devices/codecs/effects/...

	\see \ref phonon_Backend_xName
	\see \ref phonon_Backend_xDescription

\subsection phonon_Backend_xName QString <device/codec/effect/...>Name( int index )
	Returns the name of the given device/codec/effect/...

	\param index The index of one device/codec/effect/... this is one index
	out of \ref phonon_Backend_xIndexes
	
	\returns A translated user visible string to name the device.

	\see \ref phonon_Backend_xIndexes
	\see \ref phonon_Backend_xDescription
\subsection phonon_Backend_xDescription QString <device/codec/effect/...>Description( int index )
	Returns the description of the given device/codec/effect/...

	\param index The index of one device/codec/effect/... this is one index
	out of \ref phonon_Backend_xIndexes
	
	\returns A translated user visible string to describe the device.

	\see \ref phonon_Backend_xIndexes
	\see \ref phonon_Backend_xName

\subsection phonon_Backend_audioCaptureDeviceVideoIndex qint32 audioCaptureDeviceVideoIndex( int index )
	\param index The index of the device. This is one of the indexes the backend
	returned via \ref phonon_Backend_xIndexes
	\returns An index of a video capture device that is associated with the given
	audio capture device. For example a webcam might have both a video and an audio
	capture device, and in order give the user a hint that the audio and video
	capture devices belong together this index is used.
	\returns If there is no associated video capture device return -1.

\subsection phonon_Backend_videoCaptureDeviceAudioIndex qint32 videoCaptureDeviceAudioIndex( int index )
	\param index The index of the device. This is one of the indexes the backend
	returned via \ref phonon_Backend_xIndexes
	\returns An index of a audio capture device that is associated with the given
	video capture device. For example a webcam might have both a audio and an video
	capture device, and in order give the user a hint that the video and audio
	capture devices belong together this index is used.
	\returns If there is no associated audio capture device return -1.

\page phonon_AudioDataOutput The AudioDataOutput Class
\ingroup Backend

\page phonon_AudioOutput The AudioOutput Class
\ingroup Backend

\page phonon_VideoDataOutput The VideoDataOutput Class
\ingroup Backend

\page phonon_VideoWidget The VideoWidget Class
\ingroup Backend

\page phonon_Effect The Effect Class
\ingroup Backend

\page phonon_BrightnessControl The BrightnessControl Class
\ingroup Backend

\page phonon_VideoEffect The VideoEffect Class
\ingroup Backend

\page phonon_Visualization The Visualization Class
\ingroup Backend

\page phonon_VolumeFaderEffect The VolumeFaderEffect Class
\ingroup Backend

*/