Expose the audio category information for streams.

QAudioOutput and QSoundEffect now have a category property so that
system volume mixing or processing can be applied.

Initially just pulseaudio supports this but Windows Vista etc should also
work.

Change-Id: I6855b08367e5a055ac7dfcffd644c98bfd7c5a4e
Reviewed-by: Ling Hu <ling.hu@nokia.com>

src/multimedia/audio/qaudiooutput.cpp

@@ -363,6 +363,41 @@ qreal QAudioOutput::volume() const
     return d->volume();
 }
 
+/*!
+    Returns the audio category of this audio stream.
+
+    Some platforms can group audio streams into categories
+    and manage their volumes independently, or display them
+    in a system mixer control.  You can set this property to
+    allow the platform to distinguish the purpose of your streams.
+
+    \sa setCategory()
+*/
+QString QAudioOutput::category() const
+{
+    return d->category();
+}
+
+/*!
+    Sets the audio category of this audio stream.
+
+    Some platforms can group audio streams into categories
+    and manage their volumes independently, or display them
+    in a system mixer control.  You can set this property to
+    allow the platform to distinguish the purpose of your streams.
+
+    Not all platforms support audio stream categorization.  In this
+    case, the function call will be ignored.
+
+    Changing an audio output stream's category while it is opened
+    will not take effect until it is reopened.
+    \sa category()
+*/
+void QAudioOutput::setCategory(const QString &category)
+{
+    d->setCategory(category);
+}
+
 /*!
     \fn QAudioOutput::stateChanged(QAudio::State state)
     This signal is emitted when the device \a state has changed.

src/multimedia/audio/qaudiooutput.h

@@ -100,6 +100,9 @@ public:
     void setVolume(qreal);
     qreal volume() const;
 
+    QString category() const;
+    void setCategory(const QString &category);
+
 Q_SIGNALS:
     void stateChanged(QAudio::State);
     void notify();

src/multimedia/audio/qaudiosystem.h

@@ -97,6 +97,8 @@ public:
     virtual QAudioFormat format() const = 0;
     virtual void setVolume(qreal) {}
     virtual qreal volume() const { return 1.0; }
+    virtual QString category() const { return QString(); }
+    virtual void setCategory(const QString &) { }
 
 Q_SIGNALS:
     void errorChanged(QAudio::Error);

src/multimedia/audio/qsoundeffect.cpp

@@ -218,6 +218,7 @@ QSoundEffect::QSoundEffect(QObject *parent) :
     connect(d, SIGNAL(loadedChanged()), SIGNAL(loadedChanged()));
     connect(d, SIGNAL(playingChanged()), SIGNAL(playingChanged()));
     connect(d, SIGNAL(statusChanged()), SIGNAL(statusChanged()));
+    connect(d, SIGNAL(categoryChanged()), SIGNAL(categoryChanged()));
 }
 
 /*!
@@ -366,6 +367,57 @@ QSoundEffect::Status QSoundEffect::status() const
     return d->status();
 }
 
+/*!
+    \qmlproperty string QtMultimedia5::SoundEffect::category
+    \property QSoundEffect::category
+
+    This property contains the \e category of this sound effect.
+
+    Some platforms can perform different audio routing
+    for different categories, or may allow the user to
+    set different volume levels for different categories.
+
+    This setting will be ignored on platforms that do not
+    support audio categories.
+*/
+/*!
+    Returns the current \e category for this sound effect.
+
+    Some platforms can perform different audio routing
+    for different categories, or may allow the user to
+    set different volume levels for different categories.
+
+    This setting will be ignored on platforms that do not
+    support audio categories.
+
+    \sa setCategory()
+*/
+QString QSoundEffect::category() const
+{
+    return d->category();
+}
+
+/*!
+    Sets the \e category of this sound effect to \a category.
+
+    Some platforms can perform different audio routing
+    for different categories, or may allow the user to
+    set different volume levels for different categories.
+
+    This setting will be ignored on platforms that do not
+    support audio categories.
+
+    If this setting is changed while a sound effect is playing
+    it will only take effect when the sound effect has stopped
+    playing.
+
+    \sa category()
+ */
+void QSoundEffect::setCategory(const QString &category)
+{
+    d->setCategory(category);
+}
+
 
 /*!
   \qmlmethod QtMultimedia5::SoundEffect::stop()

src/multimedia/audio/qsoundeffect.h

@@ -68,6 +68,7 @@ class Q_MULTIMEDIA_EXPORT QSoundEffect : public QObject
     Q_PROPERTY(bool muted READ isMuted WRITE setMuted NOTIFY mutedChanged)
     Q_PROPERTY(bool playing READ isPlaying NOTIFY playingChanged)
     Q_PROPERTY(Status status READ status NOTIFY statusChanged)
+    Q_PROPERTY(QString category READ category WRITE setCategory NOTIFY categoryChanged)
     Q_ENUMS(Loop)
     Q_ENUMS(Status)
 
@@ -108,6 +109,9 @@ public:
     bool isPlaying() const;
     Status status() const;
 
+    QString category() const;
+    void setCategory(const QString &category);
+
 Q_SIGNALS:
     void sourceChanged();
     void loopCountChanged();
@@ -117,6 +121,7 @@ Q_SIGNALS:
     void loadedChanged();
     void playingChanged();
     void statusChanged();
+    void categoryChanged();
 
 public Q_SLOTS:
     void play();

src/multimedia/audio/qsoundeffect_pulse_p.cpp

@@ -351,7 +351,8 @@ QSoundEffectPrivate::QSoundEffectPrivate(QObject* parent):
     m_volume(100),
     m_loopCount(1),
     m_runningCount(0),
-    m_sample(0) ,
+    m_sample(0),
+    m_reloadCategory(false),
     m_position(0)
 {
     m_ref = new QSoundEffectRef(this);
@@ -373,6 +374,32 @@ void QSoundEffectPrivate::release()
     this->deleteLater();
 }
 
+QString QSoundEffectPrivate::category() const
+{
+    return m_category;
+}
+
+void QSoundEffectPrivate::setCategory(const QString &category)
+{
+    if (m_category != category) {
+        m_category = category;
+        if (m_playing || m_playQueued) {
+            // Currently playing, we need to disconnect when
+            // playback stops
+            m_reloadCategory = true;
+        } else if (m_pulseStream) {
+            // We have to disconnect and reconnect
+            unloadPulseStream();
+            createPulseStream();
+        } else {
+            // Well, next time we create the pulse stream
+            // it should be set
+        }
+
+        emit categoryChanged();
+    }
+}
+
 QSoundEffectPrivate::~QSoundEffectPrivate()
 {
     m_ref->release();
@@ -700,6 +727,7 @@ void QSoundEffectPrivate::unloadPulseStream()
         pa_stream_unref(m_pulseStream);
         disconnect(pulseDaemon(), SIGNAL(volumeChanged()), this, SLOT(updateVolume()));
         m_pulseStream = 0;
+        m_reloadCategory = false; // category will be reloaded when we connect anyway
     }
 }
 
@@ -808,11 +836,16 @@ void QSoundEffectPrivate::stop()
     setPlaying(false);
     PulseDaemonLocker locker;
     m_stopping = true;
-    if (m_pulseStream)
+    if (m_pulseStream) {
         emptyStream();
+        if (m_reloadCategory) {
+            unloadPulseStream(); // upon play we reconnect anyway
+        }
+    }
     setLoopsRemaining(0);
     m_position = 0;
     m_playQueued = false;
+    m_reloadCategory = false;
 }
 
 void QSoundEffectPrivate::underRun()
@@ -846,7 +879,12 @@ void QSoundEffectPrivate::createPulseStream()
 #endif
 
     pa_proplist *propList = pa_proplist_new();
-    pa_proplist_sets(propList, PA_PROP_MEDIA_ROLE, "soundeffect");
+    if (m_category.isNull()) {
+        // Meant to be one of the strings "video", "music", "game", "event", "phone", "animation", "production", "a11y", "test"
+        pa_proplist_sets(propList, PA_PROP_MEDIA_ROLE, "game");
+    } else {
+        pa_proplist_sets(propList, PA_PROP_MEDIA_ROLE, m_category.toLatin1().constData());
+    }
     pa_stream *stream = pa_stream_new_with_proplist(pulseDaemon()->context(), m_name.constData(), &m_pulseSpec, 0, propList);
     pa_proplist_free(propList);
 

src/multimedia/audio/qsoundeffect_pulse_p.h

@@ -94,6 +94,9 @@ public:
 
     void release();
 
+    QString category() const;
+    void setCategory(const QString &category);
+
 public Q_SLOTS:
     void play();
     void stop();
@@ -105,6 +108,7 @@ Q_SIGNALS:
     void loadedChanged();
     void playingChanged();
     void statusChanged();
+    void categoryChanged();
 
 private Q_SLOTS:
     void decoderError();
@@ -157,6 +161,8 @@ private:
     int     m_runningCount;
     QUrl    m_source;
     QByteArray m_name;
+    QString m_category;
+    bool m_reloadCategory;
 
     QSample *m_sample;
     int m_position;

src/multimedia/audio/qsoundeffect_qmedia_p.cpp

@@ -250,6 +250,20 @@ void QSoundEffectPrivate::setLoopsRemaining(int loopsRemaining)
     emit loopsRemainingChanged();
 }
 
+/* Categories are ignored */
+QString QSoundEffectPrivate::category() const
+{
+    return m_category;
+}
+
+void QSoundEffectPrivate::setCategory(const QString &category)
+{
+    if (m_category != category && !m_playing) {
+        m_category = category;
+        emit categoryChanged();
+    }
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qsoundeffect_qmedia_p.cpp"

src/multimedia/audio/qsoundeffect_qmedia_p.h

@@ -91,6 +91,10 @@ public:
 
     void release();
 
+    // Categories are not really supported with QMediaPlayer
+    QString category() const;
+    void setCategory(const QString &);
+
 public Q_SLOTS:
     void play();
     void stop();
@@ -102,6 +106,7 @@ Q_SIGNALS:
     void loadedChanged();
     void playingChanged();
     void statusChanged();
+    void categoryChanged();
 
 private Q_SLOTS:
     void stateChanged(QMediaPlayer::State);
@@ -118,6 +123,7 @@ private:
     bool           m_playing;
     QSoundEffect::Status  m_status;
     QMediaPlayer  *m_player;
+    QString         m_category;
 };
 
 QT_END_NAMESPACE

src/plugins/pulseaudio/qaudiooutput_pulse.cpp

@@ -53,6 +53,7 @@
 QT_BEGIN_NAMESPACE
 
 const int PeriodTimeMs = 20;
+const int LowLatencyBufferSizeMs = 40;
 
 static void  outputStreamWriteCallback(pa_stream *stream, size_t length, void *userdata)
 {
@@ -267,7 +268,23 @@ bool QPulseAudioOutput::open()
 
     QPulseAudioEngine *pulseEngine = QPulseAudioEngine::instance();
     pa_threaded_mainloop_lock(pulseEngine->mainloop());
-    m_stream = pa_stream_new(pulseEngine->context(), m_streamName.constData(), &spec, 0);
+
+    pa_proplist *propList = pa_proplist_new();
+    if (m_category.isNull()) {
+        // Meant to be one of the strings "video", "music", "game", "event", "phone", "animation", "production", "a11y", "test"
+        // We choose music unless the buffer size is small, where we choose game..
+        qint64 bytesPerSecond = m_format.sampleRate() * m_format.channels() * m_format.sampleSize() / 8;
+        if (m_bufferSize > 0 && bytesPerSecond > 0 && (m_bufferSize * 1000LL / bytesPerSecond < LowLatencyBufferSizeMs)) {
+            pa_proplist_sets(propList, PA_PROP_MEDIA_ROLE, "game");
+        } else {
+            pa_proplist_sets(propList, PA_PROP_MEDIA_ROLE, "music");
+        }
+    } else {
+        pa_proplist_sets(propList, PA_PROP_MEDIA_ROLE, m_category.toLatin1().constData());
+    }
+
+    m_stream = pa_stream_new_with_proplist(pulseEngine->context(), m_streamName.constData(), &spec, 0, propList);
+    pa_proplist_free(propList);
 
     pa_stream_set_state_callback(m_stream, outputStreamStateCallback, this);
     pa_stream_set_write_callback(m_stream, outputStreamWriteCallback, this);
@@ -619,6 +636,18 @@ qreal QPulseAudioOutput::volume() const
     return m_volume;
 }
 
+void QPulseAudioOutput::setCategory(const QString &category)
+{
+    if (m_category != category) {
+        m_category = category;
+    }
+}
+
+QString QPulseAudioOutput::category() const
+{
+    return m_category;
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qaudiooutput_pulse.cpp"

src/plugins/pulseaudio/qaudiooutput_pulse.h

@@ -98,6 +98,9 @@ public:
     void setVolume(qreal volume);
     qreal volume() const;
 
+    void setCategory(const QString &category);
+    QString category() const;
+
 public:
     void streamUnderflowCallback();
 
@@ -130,6 +133,7 @@ private:
     QTime m_timeStamp;
     qint64 m_elapsedTimeOffset;
     bool m_resuming;
+    QString m_category;
 
     qreal m_volume;
     pa_cvolume m_chVolume;