Add a Surround mode to QAudioEngine

So far, we only had a Normal and Headphone mode here. Extend this
to cover Surround configurations, and explicit Stereo mode and
the Headphone mode.

Change-Id: I086d02157d4edfd92e5b24076bee9a51bb5cc68a
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

6 files changed, 33 insertions, 22 deletions

diff --git a/examples/multimedia/spatialaudio/main.cpp b/examples/multimedia/spatialaudio/main.cpp
index b49396013..8aa9bb672 100644
--- a/examples/multimedia/spatialaudio/main.cpp
+++ b/examples/multimedia/spatialaudio/main.cpp
@@ -85,24 +85,28 @@ public:
 
         roomDimension = new QSlider(Qt::Horizontal);
         roomDimension->setRange(0, 10000);
-        roomDimension->setValue(500);
+        roomDimension->setValue(1000);
         grid->addWidget(new QLabel(tr("Room dimension (0 - 100 meter):")), 5, 0);
         grid->addWidget(roomDimension, 5, 1);
 
         reverbGain = new QSlider(Qt::Horizontal);
         reverbGain->setRange(0, 500);
-        reverbGain->setValue(100);
+        reverbGain->setValue(0);
         grid->addWidget(new QLabel(tr("Reverb gain (0-5):")), 6, 0);
         grid->addWidget(reverbGain, 6, 1);
 
         reflectionGain = new QSlider(Qt::Horizontal);
         reflectionGain->setRange(0, 500);
-        reflectionGain->setValue(100);
+        reflectionGain->setValue(0);
         grid->addWidget(new QLabel(tr("Reflection gain (0-5):")), 7, 0);
         grid->addWidget(reflectionGain, 7, 1);
 
-        useHeadphone = new QCheckBox(tr("Use headphone spatialization"));
-        grid->addWidget(useHeadphone, 8, 1, 1, 2);
+        mode = new QComboBox;
+        mode->addItem(tr("Surround"), QVariant::fromValue(QAudioEngine::Surround));
+        mode->addItem(tr("Stereo"), QVariant::fromValue(QAudioEngine::Stereo));
+        mode->addItem(tr("Headphone"), QVariant::fromValue(QAudioEngine::Headphone));
+        grid->addWidget(new QLabel(tr("Output mode:")), 8, 0);
+        grid->addWidget(mode, 8, 1);
 
         connect(fileEdit, &QLineEdit::textChanged, this, &AudioWidget::fileChanged);
         connect(fileDialogButton, &QPushButton::clicked, this, &AudioWidget::openFileDialog);
@@ -116,18 +120,16 @@ public:
         connect(reverbGain, &QSlider::valueChanged, this, &AudioWidget::updateRoom);
         connect(reflectionGain, &QSlider::valueChanged, this, &AudioWidget::updateRoom);
 
-        connect(useHeadphone, &QCheckBox::stateChanged, this, &AudioWidget::useHeadphoneChanged);
+        connect(mode, &QComboBox::currentIndexChanged, this, &AudioWidget::modeChanged);
 
         room = new QAudioRoom(&engine);
-        room->setDimensions(QVector3D(5, 5, 5));
         room->setWallMaterial(QAudioRoom::BackWall, QAudioRoom::BrickBare);
         room->setWallMaterial(QAudioRoom::FrontWall, QAudioRoom::BrickBare);
         room->setWallMaterial(QAudioRoom::LeftWall, QAudioRoom::BrickBare);
         room->setWallMaterial(QAudioRoom::RightWall, QAudioRoom::BrickBare);
         room->setWallMaterial(QAudioRoom::Floor, QAudioRoom::Marble);
         room->setWallMaterial(QAudioRoom::Ceiling, QAudioRoom::WoodCeiling);
-        room->setReverbGain(1);
-        room->setReflectionGain(1);
+        updateRoom();
 
         listener = new QAudioListener(&engine);
         listener->setPosition({});
@@ -185,7 +187,7 @@ private slots:
     QSlider *roomDimension = nullptr;
     QSlider *reverbGain = nullptr;
     QSlider *reflectionGain = nullptr;
-    QCheckBox *useHeadphone = nullptr;
+    QComboBox *mode = nullptr;
 
     QAudioEngine engine;
     QAudioListener *listener = nullptr;
diff --git a/src/multimedia/spatial/qaudioengine.cpp b/src/multimedia/spatial/qaudioengine.cpp
index c88251b34..a0c33bb63 100644
--- a/src/multimedia/spatial/qaudioengine.cpp
+++ b/src/multimedia/spatial/qaudioengine.cpp
@@ -147,7 +147,7 @@ qint64 QAudioOutputStream::readData(char *data, qint64 len)
             d->api->SetInterleavedBuffer(sp->sourceId, buf, 2, QAudioEnginePrivate::bufferSize);
         }
 
-        if (d->ambisonicDecoder && d->outputMode == QAudioEngine::Normal && d->format.channelCount() != 2) {
+        if (d->ambisonicDecoder && d->outputMode == QAudioEngine::Surround) {
             const float *channels[QAmbisonicDecoder::maxAmbisonicChannels];
             int nSamples = vraudio::getAmbisonicOutput(d->api, channels, d->ambisonicDecoder->nInputChannels());
             Q_ASSERT(d->ambisonicDecoder->nOutputChannels() <= 8);
@@ -361,10 +361,13 @@ QAudioEngine::~QAudioEngine()
 }
 
 /*! \enum QAudioEngine::OutputMode
-    \value Normal Map the sounds to the loudspeaker configuration of the output device.
-    This is normally a stereo or surround speaker setup.
+    \value Surround Map the sounds to the loudspeaker configuration of the output device.
+        This is normally a stereo or surround speaker setup.
+    \value Stereo Map the sounds to the stereo loudspeaker configuration of the output device.
+        This will ignore any additional speakers and only use the left and right channels
+        to create a stero rendering of the sound field.
     \value Headphone Use Headphone spatialization to create a 3D audio effect when listening
-    to the sound field through headphones
+        to the sound field through headphones
 */
 
 /*!
@@ -379,9 +382,9 @@ void QAudioEngine::setOutputMode(OutputMode mode)
     if (d->outputMode == mode)
         return;
     d->outputMode = mode;
-    if (d->api) {
-        d->api->SetStereoSpeakerMode(mode == Normal);
-    }
+    if (d->api)
+        d->api->SetStereoSpeakerMode(mode != Headphone);
+
     emit outputModeChanged();
 }
 
@@ -452,7 +455,7 @@ void QAudioEngine::start()
     d->format.setSampleRate(d->sampleRate);
     d->format.setSampleFormat(QAudioFormat::Int16);
 
-    d->api->SetStereoSpeakerMode(d->outputMode == Normal);
+    d->api->SetStereoSpeakerMode(d->outputMode != Headphone);
     d->api->SetMasterVolume(d->masterVolume);
 
     d->outputStream.reset(new QAudioOutputStream(d));
diff --git a/src/multimedia/spatial/qaudioengine.h b/src/multimedia/spatial/qaudioengine.h
index dca0b1cc1..3044b61db 100644
--- a/src/multimedia/spatial/qaudioengine.h
+++ b/src/multimedia/spatial/qaudioengine.h
@@ -59,7 +59,8 @@ public:
     ~QAudioEngine();
 
     enum OutputMode {
-        Normal,
+        Surround,
+        Stereo,
         Headphone
     };
     Q_ENUM(OutputMode)
diff --git a/src/multimedia/spatial/qaudioengine_p.h b/src/multimedia/spatial/qaudioengine_p.h
index 36a26ec40..42ae27834 100644
--- a/src/multimedia/spatial/qaudioengine_p.h
+++ b/src/multimedia/spatial/qaudioengine_p.h
@@ -85,7 +85,7 @@ public:
     vraudio::ResonanceAudioApi *api = nullptr;
     int sampleRate = 44100;
     float masterVolume = 1.;
-    QAudioEngine::OutputMode outputMode = QAudioEngine::Normal;
+    QAudioEngine::OutputMode outputMode = QAudioEngine::Surround;
     bool roomEffectsEnabled = true;
 
     // Resonance Audio uses meters internally, while Qt Quick 3D and our API uses cm by default.
diff --git a/src/multimediaquick3d/qquick3daudioengine.cpp b/src/multimediaquick3d/qquick3daudioengine.cpp
index 5bf7608af..60f083bca 100644
--- a/src/multimediaquick3d/qquick3daudioengine.cpp
+++ b/src/multimediaquick3d/qquick3daudioengine.cpp
@@ -94,9 +94,13 @@ QQuick3DAudioEngine::~QQuick3DAudioEngine()
     \table
     \header \li Property value
             \li Description
-    \row \li Normal
+    \row \li Surround
         \li Map the sounds to the loudspeaker configuration of the output device.
             This is normally a stereo or surround speaker setup.
+    \row \li Stereo
+        \li Map the sounds to the stereo loudspeaker configuration of the output device.
+            This will ignore any additional speakers and only use the left and right channels
+            to create a stero rendering of the sound field.
     \row \li Headphone
         \li Use Headphone spatialization to create a 3D audio effect when listening
             to the sound field through headphones.
diff --git a/src/multimediaquick3d/qquick3daudioengine_p.h b/src/multimediaquick3d/qquick3daudioengine_p.h
index ed01eedc0..f44b3c0ad 100644
--- a/src/multimediaquick3d/qquick3daudioengine_p.h
+++ b/src/multimediaquick3d/qquick3daudioengine_p.h
@@ -56,7 +56,8 @@ class QQuick3DAudioEngine : public QObject
 public:
     // Keep in sync with QAudioEngine::OutputMode
     enum OutputMode {
-        Normal,
+        Surround,
+        Stereo,
         Headphone
     };
     Q_ENUM(OutputMode)