1 files changed, 88 insertions, 2 deletions
diff --git a/src/multimedia/audio/qaudiosystem.cpp b/src/multimedia/audio/qaudiosystem.cpp
index b11993e55..039ab3061 100644
--- a/src/multimedia/audio/qaudiosystem.cpp
+++ b/src/multimedia/audio/qaudiosystem.cpp
@@ -37,7 +37,14 @@
 **
 ****************************************************************************/
 
-#include "qaudiosystem.h"
+#include <private/qtmultimediaglobal_p.h>
+#include "qaudiosystem_p.h"
+
+#if QT_CONFIG(pulseaudio)
+#include <private/qaudiointerface_pulse_p.h>
+#elif QT_CONFIG(alsa)
+#include <private/qalsainterface_p.h>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -371,6 +378,85 @@ QT_BEGIN_NAMESPACE
 */
 
 
+/*!
+    \class QAudioSystemInterface
+    \internal
+    \brief The QAudioSystemInterface class provides an abstract base for audio plugins.
+
+    \ingroup multimedia
+    \ingroup multimedia_audio
+    \inmodule QtMultimedia
+
+    Writing a audio plugin is achieved by subclassing this base class,
+    reimplementing the pure virtual functions availableDevices(),
+    createInput(), createOutput() and createDeviceInfo() then exporting
+    the class with the Q_PLUGIN_METADATA() macro.
+
+    The json file containing the meta data should contain a list of keys
+    matching the plugin. Add "default" to your list of keys available
+    to override the default audio device to be provided by your plugin.
+
+    \code
+    { "Keys": [ "default" ] }
+    \endcode
+
+    Unit tests are available to help in debugging new plugins.
+
+    \sa QAbstractAudioDeviceInfo, QAbstractAudioOutput, QAbstractAudioInput
+
+    Qt comes with plugins for Windows (WinMM and WASAPI), Linux (ALSA and PulseAudio), \macos / iOS
+    (CoreAudio), Android (OpenSL ES) and QNX.
+
+    If no audio plugins are available, a fallback dummy backend will be used.
+    This should print out warnings if this is the case when you try and use QAudioInput
+    or QAudioOutput. To fix this problem, make sure the dependencies for the Qt plugins are
+    installed on the system and reconfigure Qt (e.g. alsa-devel package on Linux), or create your
+    own plugin with a default key to always override the dummy fallback. The easiest way to
+    determine if you have only a dummy backend is to get a list of available audio devices.
+
+    QAudioDeviceInfo::availableDevices(QAudio::AudioOutput).size() = 0 (dummy backend)
+*/
+
+QAudioSystemInterface *QAudioSystemInterface::instance()
+{
+    static QAudioSystemInterface *system = nullptr;
+    if (!system) {
+#if QT_CONFIG(pulseaudio)
+       system = new QPulseAudioInterface();
+#elif QT_CONFIG(alsa)
+        system = new QAlsaInterface();
+#endif
+    }
+    return system;
+}
+
+QAudioSystemInterface::~QAudioSystemInterface()
+{
+
+}
+
+/*!
+    \fn QList<QByteArray> QAudioSystemInterface::availableDevices(QAudio::Mode mode) const
+    Returns a list of available audio devices for \a mode
+*/
+
+/*!
+    \fn QAbstractAudioInput* QAudioSystemInterface::createInput(const QByteArray& device)
+    Returns a pointer to a QAbstractAudioInput created using \a device identifier
+*/
+
+/*!
+    \fn QAbstractAudioOutput* QAudioSystemInterface::createOutput(const QByteArray& device)
+    Returns a pointer to a QAbstractAudioOutput created using \a device identifier
+
+*/
+
+/*!
+    \fn QAbstractAudioDeviceInfo* QAudioSystemInterface::createDeviceInfo(const QByteArray& device, QAudio::Mode mode)
+    Returns a pointer to a QAbstractAudioDeviceInfo created using \a device and \a mode
+
+*/
+
 QT_END_NAMESPACE
 
-#include "moc_qaudiosystem.cpp"
+#include "moc_qaudiosystem_p.cpp"