A number of documentation fixes.

* Remove references to private QMediaServiceProvider class and point
  new backend writers to irc/mailing lists
* Wrong or missing parameter names
* Fix a few links
* Correct a few property data types
* Various other things to keep qdoc happier

Change-Id: I5c8800d65c00f0783541afef35990bd3918acab7
Reviewed-by: Angus Cummings <angus.cummings@nokia.com>
Reviewed-by: Ling Hu <ling.hu@nokia.com>
Reviewed-by: Daniel Kovacic <daniel.kovacic@nokia.com>

src/multimedia/audio/qaudiooutput.cpp

@@ -379,7 +379,7 @@ QString QAudioOutput::category() const
 }
 
 /*!
-    Sets the audio category of this audio stream.
+    Sets the audio category of this audio stream to \a category.
 
     Some platforms can group audio streams into categories
     and manage their volumes independently, or display them

src/multimedia/controls/qmediarecordercontrol.cpp

@@ -54,14 +54,14 @@ QT_BEGIN_NAMESPACE
     \brief The QMediaRecorderControl class provides access to the recording
     functionality of a QMediaService.
 
+    Generally you will use the QMediaRecorder class in application code - this
+    class is mostly used when implementing a new QMediaService or if there is
+    access to specific low level functionality not otherwise present in QMediaRecorder.
+
     If a QMediaService can record media it will implement QMediaRecorderControl.
     This control provides a means to set the \l {outputLocation()}{output location},
-    and \l {record()}{start}, \l {pause()}{pause} and \l {stop()}{stop}
-    recording.  It also provides feedback on the \l {duration()}{duration}
-    of the recording.
-
-    The functionality provided by this control is exposed to application
-    code through the QMediaRecorder class.
+    and record, pause and stop recording via the \l setState() method.  It also
+    provides feedback on the \l {duration()}{duration} of the recording.
 
     The interface name of QMediaRecorderControl is \c org.qt-project.qt.mediarecordercontrol/5.0 as
     defined in QMediaRecorderControl_iid.

src/multimedia/playback/qmediaplayer.cpp

@@ -83,7 +83,7 @@ QT_BEGIN_NAMESPACE
     functions for things like:
 
     \list
-    \li Accessing the currently playing media's metadata (\l {QMediaObject::metaData()} and \l predefined \l {QtMultimedia::MetaData}{meta-data keys})
+    \li Accessing the currently playing media's metadata (\l {QMediaObject::metaData()} and \l {QtMultimedia::MetaData}{predefined meta-data keys})
     \li Checking to see if the media playback service is currently available (\l {QMediaObject::availabilityError()})
     \endlist
 

src/multimedia/qmediaservice.cpp

@@ -76,9 +76,11 @@ QT_BEGIN_NAMESPACE
     Media objects can use services loaded dynamically from plug-ins or
     implemented statically within an applications.  Plug-in based services
     should also implement the QMediaServiceProviderPlugin interface.  Static
-    services should implement the QMediaServiceProvider interface.
+    services should implement the QMediaServiceProvider interface.  In general,
+    implementing a QMediaService is outside of the scope of this documentation
+    and support on the relevant mailing lists or IRC channels should be sought.
 
-    \sa QMediaObject, QMediaControl, QMediaServiceProvider, QMediaServiceProviderPlugin
+    \sa QMediaObject, QMediaControl
 */
 
 /*!

src/multimedia/recording/qmediaencodersettings.cpp

@@ -342,7 +342,7 @@ QVariantMap QAudioEncoderSettings::encodingOptions() const
 }
 
 /*!
-    Set the encoding \a option \a value.
+    Set the encoding \a option to \a value.
 
     The supported set and meaning of encoding options are
     system and selected codec specific.
@@ -359,12 +359,12 @@ void QAudioEncoderSettings::setEncodingOption(const QString &option, const QVari
 }
 
 /*!
-    Replace all the \a encoding options.
+    Replace all the encoding options with \a options.
 
     The supported set and meaning of encoding options are
     system and selected codec specific.
 
-    \sa encodingOption(), setEncodingOptions()
+    \sa encodingOption(), setEncodingOption()
 */
 void QAudioEncoderSettings::setEncodingOptions(const QVariantMap &options)
 {
@@ -687,12 +687,12 @@ void QVideoEncoderSettings::setEncodingOption(const QString &option, const QVari
 }
 
 /*!
-    Replace all the \a encoding options.
+    Replace all the encoding options with \a options.
 
     The supported set and meaning of encoding options are
     system and selected codec specific.
 
-    \sa encodingOption(), setEncodingOptions()
+    \sa encodingOption(), setEncodingOption()
 */
 void QVideoEncoderSettings::setEncodingOptions(const QVariantMap &options)
 {
@@ -932,12 +932,12 @@ void QImageEncoderSettings::setEncodingOption(const QString &option, const QVari
 }
 
 /*!
-    Replace all the \a encoding options.
+    Replace all the encoding options with \a options.
 
     The supported set and meaning of encoding options are
     system and selected codec specific.
 
-    \sa encodingOption(), setEncodingOptions()
+    \sa encodingOption(), setEncodingOption()
 */
 void QImageEncoderSettings::setEncodingOptions(const QVariantMap &options)
 {