Add support for selecting audio/video tracks

Implement this for the gstreamer backend. The API
for subtitle tracks is also there, but we do not
support displaying those for the moment.

Change-Id: Ia561656d63c33ac4ea5d167846d4535820180fb3
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Doris Verria <doris.verria@qt.io>

8 files changed, 260 insertions, 51 deletions

diff --git a/examples/multimediawidgets/player/player.cpp b/examples/multimediawidgets/player/player.cpp
index 6c4df136c..7f7657ce2 100644
--- a/examples/multimediawidgets/player/player.cpp
+++ b/examples/multimediawidgets/player/player.cpp
@@ -91,6 +91,7 @@ Player::Player(QWidget *parent)
     connect(m_player, &QMediaPlayer::videoAvailableChanged, this, &Player::videoAvailableChanged);
     connect(m_player, QOverload<QMediaPlayer::Error>::of(&QMediaPlayer::error), this, &Player::displayErrorMessage);
     connect(m_player, &QMediaPlayer::stateChanged, this, &Player::stateChanged);
+    connect(m_player, &QMediaPlayer::tracksChanged, this, &Player::tracksChanged);
 
     m_playlistView = new QListView(this);
     m_playlistView->setModel(m_playlistModel);
@@ -104,6 +105,20 @@ Player::Player(QWidget *parent)
     m_labelDuration = new QLabel(this);
     connect(m_slider, &QSlider::sliderMoved, this, &Player::seek);
 
+    m_audioTracks = new QComboBox(this);
+    m_videoTracks = new QComboBox(this);
+    m_subtitleTracks = new QComboBox(this);
+    connect(m_audioTracks, &QComboBox::activated, this, &Player::selectAudioStream);
+    connect(m_videoTracks, &QComboBox::activated, this, &Player::selectVideoStream);
+    connect(m_subtitleTracks, &QComboBox::activated, this, &Player::selectSubtitleStream);
+    QGridLayout *tracksLayout = new QGridLayout;
+    tracksLayout->addWidget(new QLabel(tr("Audio Tracks:"), this), 0, 0);
+    tracksLayout->addWidget(m_audioTracks, 0, 1);
+    tracksLayout->addWidget(new QLabel(tr("Video Tracks:"), this), 1, 0);
+    tracksLayout->addWidget(m_videoTracks, 1, 1);
+    tracksLayout->addWidget(new QLabel(tr("Subtitle Tracks:"), this), 2, 0);
+    tracksLayout->addWidget(m_subtitleTracks, 2, 1);
+
     m_labelHistogram = new QLabel(this);
     m_labelHistogram->setText("Histogram:");
     m_videoHistogram = new HistogramWidget(this);
@@ -201,6 +216,7 @@ Player::Player(QWidget *parent)
     hLayout->addWidget(m_labelDuration);
     layout->addLayout(hLayout);
     layout->addLayout(controlLayout);
+    layout->addLayout(tracksLayout);
     layout->addLayout(histogramLayout);
     layout->addWidget(metaDataLabel);
     layout->addLayout(metaDataLayout);
@@ -326,6 +342,25 @@ void Player::metaDataChanged()
     }
 }
 
+void Player::tracksChanged()
+{
+    m_audioTracks->clear();
+    m_videoTracks->clear();
+    m_subtitleTracks->clear();
+
+    const auto audioStreams = m_player->audioTracks();
+    for (int i = 0; i < audioStreams.size(); ++i)
+        m_audioTracks->addItem(audioStreams.at(i).stringValue(QMediaMetaData::Language), i);
+
+    const auto videoStreams = m_player->videoTracks();
+    for (int i = 0; i < videoStreams.size(); ++i)
+        m_videoTracks->addItem(videoStreams.at(i).stringValue(QMediaMetaData::Language), i);
+
+    const auto subtitleStreams = m_player->subtitleTracks();
+    for (int i = 0; i < subtitleStreams.size(); ++i)
+        m_subtitleTracks->addItem(subtitleStreams.at(i).stringValue(QMediaMetaData::Language), i);
+}
+
 void Player::previousClicked()
 {
     // Go to previous track if we are within the first 5 seconds of playback
@@ -429,6 +464,24 @@ void Player::videoAvailableChanged(bool available)
     m_colorButton->setEnabled(available);
 }
 
+void Player::selectAudioStream()
+{
+    int stream = m_audioTracks->currentData().toInt();
+    m_player->setActiveAudioTrack(stream);
+}
+
+void Player::selectVideoStream()
+{
+    int stream = m_audioTracks->currentData().toInt();
+    m_player->setActiveVideoTrack(stream);
+}
+
+void Player::selectSubtitleStream()
+{
+    int stream = m_audioTracks->currentData().toInt();
+    m_player->setActiveSubtitleTrack(stream);
+}
+
 void Player::setTrackInfo(const QString &info)
 {
     m_trackInfo = info;
diff --git a/examples/multimediawidgets/player/player.h b/examples/multimediawidgets/player/player.h
index 3944d0f3f..7385d27a9 100644
--- a/examples/multimediawidgets/player/player.h
+++ b/examples/multimediawidgets/player/player.h
@@ -92,6 +92,7 @@ private slots:
     void durationChanged(qint64 duration);
     void positionChanged(qint64 progress);
     void metaDataChanged();
+    void tracksChanged();
 
     void previousClicked();
 
@@ -104,6 +105,10 @@ private slots:
     void bufferingProgress(int progress);
     void videoAvailableChanged(bool available);
 
+    void selectAudioStream();
+    void selectVideoStream();
+    void selectSubtitleStream();
+
     void displayErrorMessage();
 
     void showColorDialog();
@@ -129,6 +134,10 @@ private:
     QLabel *m_statusLabel = nullptr;
     QStatusBar *m_statusBar = nullptr;
 
+    QComboBox *m_audioTracks = nullptr;
+    QComboBox *m_videoTracks = nullptr;
+    QComboBox *m_subtitleTracks = nullptr;
+
     QLabel *m_labelHistogram = nullptr;
     HistogramWidget *m_videoHistogram = nullptr;
     HistogramWidget *m_audioHistogram = nullptr;
diff --git a/src/multimedia/platform/gstreamer/common/qgst_p.h b/src/multimedia/platform/gstreamer/common/qgst_p.h
index 3bfa2503a..b779960f9 100644
--- a/src/multimedia/platform/gstreamer/common/qgst_p.h
+++ b/src/multimedia/platform/gstreamer/common/qgst_p.h
@@ -236,7 +236,7 @@ public:
     QGstObject(GstObject *o, RefMode mode = HasRef)
         : m_object(o)
     {
-        if (mode == NeedsRef)
+        if (o && mode == NeedsRef)
             // Use ref_sink to remove any floating references
             gst_object_ref_sink(m_object);
     }
@@ -274,6 +274,7 @@ public:
     void set(const char *property, qint64 i) { g_object_set(m_object, property, gint64(i), nullptr); }
     void set(const char *property, quint64 i) { g_object_set(m_object, property, guint64(i), nullptr); }
     void set(const char *property, double d) { g_object_set(m_object, property, gdouble(d), nullptr); }
+    void set(const char *property, const QGstObject &o) { g_object_set(m_object, property, o.object(), nullptr); }
 
     QGString getString(const char *property) const
     { char *s = nullptr; g_object_get(m_object, property, &s, nullptr); return s; }
diff --git a/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp b/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp
index ee8e8e279..6fbaba9b1 100644
--- a/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp
+++ b/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer.cpp
@@ -39,7 +39,6 @@
 
 #include <private/qgstreamermediaplayer_p.h>
 #include <private/qgstreamerplayersession_p.h>
-#include <private/qgstreamerstreamscontrol_p.h>
 #include <private/qgstreamervideorenderer_p.h>
 #include <private/qgstreamerbushelper_p.h>
 #include <private/qgstreamermetadata_p.h>
@@ -66,24 +65,24 @@ QT_BEGIN_NAMESPACE
 QGstreamerMediaPlayer::QGstreamerMediaPlayer(QObject *parent)
     : QPlatformMediaPlayer(parent)
 {
-    audioInputSelector = QGstElement("input-selector", "audioInputSelector");
+    inputSelector[AudioStream] = QGstElement("input-selector", "audioInputSelector");
     audioQueue = QGstElement("queue", "audioQueue");
     audioConvert = QGstElement("audioconvert", "audioConvert");
     audioResample = QGstElement("audioresample", "audioResample");
     audioVolume = QGstElement("volume", "volume");
     audioSink = QGstElement("autoaudiosink", "autoAudioSink");
-    playerPipeline.add(audioInputSelector, audioQueue, audioConvert, audioResample, audioVolume, audioSink);
-    audioInputSelector.link(audioQueue, audioConvert, audioResample, audioVolume, audioSink);
+    playerPipeline.add(inputSelector[AudioStream], audioQueue, audioConvert, audioResample, audioVolume, audioSink);
+    inputSelector[AudioStream].link(audioQueue, audioConvert, audioResample, audioVolume, audioSink);
 
-    videoInputSelector = QGstElement("input-selector", "videoInputSelector");
+    inputSelector[VideoStream] = QGstElement("input-selector", "videoInputSelector");
     videoQueue = QGstElement("queue", "videoQueue");
     videoConvert = QGstElement("videoconvert", "videoConvert");
     videoScale = QGstElement("videoscale", "videoScale");
-    playerPipeline.add(videoInputSelector, videoQueue, videoConvert, videoScale);
-    videoInputSelector.link(videoQueue, videoConvert, videoScale);
+    playerPipeline.add(inputSelector[VideoStream], videoQueue, videoConvert, videoScale);
+    inputSelector[VideoStream].link(videoQueue, videoConvert, videoScale);
 
-    subTitleInputSelector = QGstElement("input-selector", "subTitleInputSelector");
-    playerPipeline.add(subTitleInputSelector);
+    inputSelector[SubtitleStream] = QGstElement("input-selector", "subTitleInputSelector");
+    playerPipeline.add(inputSelector[SubtitleStream]);
 
     playerPipeline.setState(GST_STATE_NULL);
 
@@ -300,12 +299,16 @@ void QGstreamerMediaPlayer::busMessage(const QGstreamerMessage &message)
             QMediaPlayer::State prevState = m_state;
             m_state = QMediaPlayer::PausedState;
 
-            //check for seekable
-            if (oldState == GST_STATE_READY) {
+            if (prerolling) {
+                prerolling = false;
+                GST_DEBUG_BIN_TO_DOT_FILE(playerPipeline.bin(), GST_DEBUG_GRAPH_SHOW_ALL, "playerPipeline");
+
                 parseStreamsAndMetadata();
 
                 if (!qFuzzyCompare(m_playbackRate, qreal(1.0)))
                     playerPipeline.seek(playerPipeline.position(), m_playbackRate);
+
+                emit tracksChanged();
             }
 
             if (m_state != prevState)
@@ -473,26 +476,38 @@ void QGstreamerMediaPlayer::decoderPadAdded(const QGstElement &src, const QGstPa
     qCDebug(qLcMediaPlayer) << "Received new pad" << pad.name() << "from" << src.name() << "type" << type;
     qCDebug(qLcMediaPlayer) << "    " << caps.toString();
 
-    QGstElement selector;
+    TrackType streamType = NTrackTypes;
     if (type.startsWith("video/x-raw")) {
-        selector = videoInputSelector;
+        streamType = VideoStream;
     } else if (type.startsWith("audio/x-raw")) {
-        selector = audioInputSelector;
+        streamType = AudioStream;
     } else if (type.startsWith("text/")) {
-        selector = subTitleInputSelector;
+        streamType = SubtitleStream;
     } else {
-        qCWarning(qLcMediaPlayer) << "Failed to add fake sink to unknown pad." << pad.name() << type;
+        qCWarning(qLcMediaPlayer) << "Ignoring unknown media stream:" << pad.name() << type;
         return;
     }
-    QGstPad sinkPad = selector.getRequestPad("sink_%u");
+    QGstPad sinkPad = inputSelector[streamType].getRequestPad("sink_%u");
     if (!pad.link(sinkPad))
           qCWarning(qLcMediaPlayer) << "Failed to link video pads.";
+    m_streams[streamType].append(sinkPad);
+
+    if (!prerolling)
+        emit tracksChanged();
 
     decoderOutputMap.insert(pad.name(), sinkPad);
 }
 
 void QGstreamerMediaPlayer::decoderPadRemoved(const QGstElement &src, const QGstPad &pad)
 {
+    int streamType;
+    for (streamType = 0; streamType < NTrackTypes; ++streamType) {
+        if (src == inputSelector[streamType])
+            break;
+    }
+    if (streamType == NTrackTypes)
+        return;
+
     qCDebug(qLcMediaPlayer) << "Removed pad" << pad.name() << "from" << src.name();
     QGstPad peer = decoderOutputMap.value(pad.name());
     if (peer.isNull())
@@ -500,12 +515,12 @@ void QGstreamerMediaPlayer::decoderPadRemoved(const QGstElement &src, const QGst
     QGstElement peerParent = peer.parent();
     qCDebug(qLcMediaPlayer) << "   was linked to pad" << peer.name() << "from" << peerParent.name();
     peerParent.releaseRequestPad(peer);
-}
 
-void QGstreamerMediaPlayer::padsDone(const QGstElement &/*src*/)
-{
-    qCDebug(qLcMediaPlayer) << "All pads have been added";
-    GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (playerPipeline.bin(), GST_DEBUG_GRAPH_SHOW_ALL, "playerPipeline");
+    Q_ASSERT(m_streams[streamType].indexOf(peer) != -1);
+    m_streams[streamType].removeAll(peer);
+
+    if (!prerolling)
+        emit tracksChanged();
 }
 
 void QGstreamerMediaPlayer::uridecodebinElementAddedCallback(GstElement */*uridecodebin*/, GstElement *child, QGstreamerMediaPlayer *that)
@@ -523,6 +538,8 @@ void QGstreamerMediaPlayer::setMedia(const QUrl &content, QIODevice *stream)
 {
     qCDebug(qLcMediaPlayer) << Q_FUNC_INFO << "setting location to" << content;
 
+    prerolling = true;
+
     int ret = playerPipeline.setStateSync(GST_STATE_NULL);
     if (ret == GST_STATE_CHANGE_FAILURE)
         qCDebug(qLcMediaPlayer) << "Unable to set the pipeline to the stopped state.";
@@ -564,7 +581,6 @@ void QGstreamerMediaPlayer::setMedia(const QUrl &content, QIODevice *stream)
     }
     decoder.onPadAdded<&QGstreamerMediaPlayer::decoderPadAdded>(this);
     decoder.onPadRemoved<&QGstreamerMediaPlayer::decoderPadRemoved>(this);
-    decoder.onNoMorePads<&QGstreamerMediaPlayer::padsDone>(this);
 
     if (m_state == QMediaPlayer::PlayingState) {
             int ret = playerPipeline.setState(GST_STATE_PLAYING);
@@ -780,6 +796,15 @@ void QGstreamerMediaPlayer::parseStreamsAndMetadata()
         }
     }
 
+    QGstPad sinkPad = inputSelector[VideoStream].getObject("active-pad");
+    Q_ASSERT(!sinkPad.isNull());
+    bool hasTags = g_object_class_find_property (G_OBJECT_GET_CLASS (sinkPad.object()), "tags") != NULL;
+
+    GstTagList *tl = nullptr;
+    g_object_get(sinkPad.object(), "tags", &tl, nullptr);
+    qCDebug(qLcMediaPlayer) << "    tags=" << hasTags << (tl ? gst_tag_list_to_string(tl) : "(null)");
+
+
     qCDebug(qLcMediaPlayer) << "============== end parse topology ============";
     emit metaDataChanged();
 }
@@ -797,23 +822,53 @@ void QGstreamerMediaPlayer::setVideoSurface(QAbstractVideoSurface *surface)
     updateVideoSink();
 }
 
-QMediaStreamsControl *QGstreamerMediaPlayer::mediaStreams()
+int QGstreamerMediaPlayer::trackCount(QPlatformMediaPlayer::TrackType type)
 {
-//    if (!m_streamsControl)
-//        m_streamsControl = new QGstreamerStreamsControl(m_session, this);
-    return m_streamsControl;
+    return m_streams[type].count();
+}
+
+QMediaMetaData QGstreamerMediaPlayer::trackMetaData(QPlatformMediaPlayer::TrackType type, int index)
+{
+    auto &s = m_streams[type];
+    if (index < 0 || index >= s.count())
+        return QMediaMetaData();
+
+    GstTagList *tagList;
+    g_object_get(s.at(index).object(), "tags", &tagList, nullptr);
+
+    QMediaMetaData md = QGstreamerMetaData::fromGstTagList(tagList);
+    return md;
+}
+
+int QGstreamerMediaPlayer::activeTrack(QPlatformMediaPlayer::TrackType type)
+{
+    auto &selector = inputSelector[type];
+    Q_ASSERT(!selector.isNull());
+    QGstPad activePad = selector.getObject("active-pad");
+    if (activePad.isNull())
+        return -1;
+    auto &streams = m_streams[type];
+    return streams.indexOf(activePad);
+}
+
+void QGstreamerMediaPlayer::setActiveTrack(QPlatformMediaPlayer::TrackType type, int index)
+{
+    auto &streams = m_streams[type];
+    if (index < 0 || index >= streams.count())
+        return;
+    auto &selector = inputSelector[type];
+    Q_ASSERT(!selector.isNull());
+    selector.set("active-pad", streams.at(index));
 }
 
 bool QGstreamerMediaPlayer::isAudioAvailable() const
 {
-//    return m_session->isAudioAvailable();
-    return true;
+    return !m_streams[AudioStream].isEmpty();
 }
 
 bool QGstreamerMediaPlayer::isVideoAvailable() const
 {
-//    return m_session->isVideoAvailable();
-    return true;
+    return !m_streams[VideoStream].isEmpty();
 }
 
 QT_END_NAMESPACE
diff --git a/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer_p.h b/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer_p.h
index 89a6fc250..93fea1c06 100644
--- a/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer_p.h
+++ b/src/multimedia/platform/gstreamer/common/qgstreamermediaplayer_p.h
@@ -61,7 +61,6 @@ QT_BEGIN_NAMESPACE
 
 class QNetworkAccessManager;
 class QGstreamerPlayerSession;
-class QGstreamerStreamsControl;
 class QGstreamerVideoRenderer;
 class QGstreamerBusHelper;
 class QGstreamerMessage;
@@ -108,7 +107,10 @@ public:
 
     void setVideoSurface(QAbstractVideoSurface *surface) override;
 
-    QMediaStreamsControl *mediaStreams() override;
+    int trackCount(TrackType) override;
+    QMediaMetaData trackMetaData(TrackType /*type*/, int /*streamNumber*/) override;
+    int activeTrack(TrackType) override;
+    void setActiveTrack(TrackType, int /*streamNumber*/) override;
 
 public Q_SLOTS:
     void setPosition(qint64 pos) override;
@@ -122,11 +124,12 @@ public Q_SLOTS:
 
     void busMessage(const QGstreamerMessage& message);
 
+
+
 private:
     friend class QGstreamerStreamsControl;
     void decoderPadAdded(const QGstElement &src, const QGstPad &pad);
     void decoderPadRemoved(const QGstElement &src, const QGstPad &pad);
-    void padsDone(const QGstElement &src);
     void prepareAudioOutputChange(const QGstPad &pad);
     static void uridecodebinElementAddedCallback(GstElement *uridecodebin, GstElement *child, QGstreamerMediaPlayer *that);
     bool changeAudioOutput();
@@ -134,8 +137,8 @@ private:
     void setSeekable(bool seekable);
     void parseStreamsAndMetadata();
 
-    QGstreamerStreamsControl *m_streamsControl = nullptr;
     QMediaMetaData m_metaData;
+    QList<QGstPad> m_streams[3];
 
     QMediaPlayer::State m_state = QMediaPlayer::StoppedState;
     QMediaPlayer::MediaStatus m_mediaStatus = QMediaPlayer::NoMedia;
@@ -146,6 +149,7 @@ private:
     QIODevice *m_stream = nullptr;
     bool ownStream = false;
 
+    bool prerolling = false;
     int m_volume = 100.;
     bool m_muted = false;
     double m_playbackRate = 1.;
@@ -166,9 +170,8 @@ private:
     QGstPipeline playerPipeline;
     QGstElement src;
     QGstElement decoder;
-    QGstElement audioInputSelector;
-    QGstElement videoInputSelector;
-    QGstElement subTitleInputSelector;
+    QGstElement inputSelector[3];
+
 //    QGstElement streamSynchronizer;
 
     QGstElement audioQueue;
diff --git a/src/multimedia/platform/qplatformmediaplayer_p.h b/src/multimedia/platform/qplatformmediaplayer_p.h
index 9169d7c89..6015bc52e 100644
--- a/src/multimedia/platform/qplatformmediaplayer_p.h
+++ b/src/multimedia/platform/qplatformmediaplayer_p.h
@@ -106,7 +106,13 @@ public:
 
     virtual void setVideoSurface(QAbstractVideoSurface *surface) = 0;
 
-    virtual QMediaStreamsControl *mediaStreams() { return nullptr; }
+    // media streams
+    enum TrackType { VideoStream, AudioStream, SubtitleStream, NTrackTypes };
+
+    virtual int trackCount(TrackType) { return 0; };
+    virtual QMediaMetaData trackMetaData(TrackType /*type*/, int /*streamNumber*/) { return QMediaMetaData(); }
+    virtual int activeTrack(TrackType) { return -1; }
+    virtual void setActiveTrack(TrackType, int /*streamNumber*/) {}
 
 Q_SIGNALS:
     void audioRoleChanged(QAudio::Role role);
@@ -125,6 +131,8 @@ Q_SIGNALS:
     void playbackRateChanged(qreal rate);
     void error(int error, const QString &errorString);
     void metaDataChanged();
+    void tracksChanged();
+    void activeTracksChanged();
 
 protected:
     explicit QPlatformMediaPlayer(QObject *parent = nullptr);
diff --git a/src/multimedia/playback/qmediaplayer.cpp b/src/multimedia/playback/qmediaplayer.cpp
index fef7951b5..ef264e296 100644
--- a/src/multimedia/playback/qmediaplayer.cpp
+++ b/src/multimedia/playback/qmediaplayer.cpp
@@ -101,6 +101,8 @@ public:
 
     void setMedia(const QUrl &media, QIODevice *stream = nullptr);
 
+    QList<QMediaMetaData> streamMetaData(QPlatformMediaPlayer::TrackType s) const;
+
     void _q_stateChanged(QMediaPlayer::State state);
     void _q_mediaStatusChanged(QMediaPlayer::MediaStatus status);
     void _q_error(int error, const QString &errorString);
@@ -253,6 +255,18 @@ void QMediaPlayerPrivate::setMedia(const QUrl &media, QIODevice *stream)
     qrcFile.swap(file); // Cleans up any previous file
 }
 
+QList<QMediaMetaData> QMediaPlayerPrivate::streamMetaData(QPlatformMediaPlayer::TrackType s) const
+{
+    QList<QMediaMetaData> streams;
+    if (control) {
+        int count = control->trackCount(s);
+        for (int i = 0; i < count; ++i) {
+            streams.append(control->trackMetaData(s, i));
+        }
+    }
+    return streams;
+}
+
 /*!
     Construct a QMediaPlayer instance
     parented to \a parent and with \a flags.
@@ -285,6 +299,8 @@ QMediaPlayer::QMediaPlayer(QObject *parent):
     connect(d->control, &QPlatformMediaPlayer::playbackRateChanged, this, &QMediaPlayer::playbackRateChanged);
     connect(d->control, &QPlatformMediaPlayer::bufferStatusChanged, this, &QMediaPlayer::bufferStatusChanged);
     connect(d->control, &QPlatformMediaPlayer::metaDataChanged, this, &QMediaPlayer::metaDataChanged);
+    connect(d->control, &QPlatformMediaPlayer::tracksChanged, this, &QMediaPlayer::tracksChanged);
+    connect(d->control, &QPlatformMediaPlayer::activeTracksChanged, this, &QMediaPlayer::activeTracksChanged);
 
     d->state = d->control->state();
     d->status = d->control->mediaStatus();
@@ -686,6 +702,69 @@ QAudioDeviceInfo QMediaPlayer::audioOutput() const
     return d->control->audioOutput();
 }
 
+QList<QMediaMetaData> QMediaPlayer::audioTracks() const
+{
+    Q_D(const QMediaPlayer);
+    return d->streamMetaData(QPlatformMediaPlayer::AudioStream);
+}
+
+QList<QMediaMetaData> QMediaPlayer::videoTracks() const
+{
+    Q_D(const QMediaPlayer);
+    return d->streamMetaData(QPlatformMediaPlayer::VideoStream);
+}
+
+QList<QMediaMetaData> QMediaPlayer::subtitleTracks() const
+{
+    Q_D(const QMediaPlayer);
+    return d->streamMetaData(QPlatformMediaPlayer::SubtitleStream);
+}
+
+int QMediaPlayer::activeAudioTrack() const
+{
+    Q_D(const QMediaPlayer);
+    if (d->control)
+        return d->control->activeTrack(QPlatformMediaPlayer::AudioStream);
+    return 0;
+}
+
+int QMediaPlayer::activeVideoTrack() const
+{
+    Q_D(const QMediaPlayer);
+    if (d->control)
+        return d->control->activeTrack(QPlatformMediaPlayer::VideoStream);
+    return 0;
+}
+
+int QMediaPlayer::activeSubtitleTrack() const
+{
+    Q_D(const QMediaPlayer);
+    if (d->control)
+        return d->control->activeTrack(QPlatformMediaPlayer::SubtitleStream);
+    return 0;
+}
+
+void QMediaPlayer::setActiveAudioTrack(int index)
+{
+    Q_D(QMediaPlayer);
+    if (d->control)
+        d->control->setActiveTrack(QPlatformMediaPlayer::AudioStream, index);
+}
+
+void QMediaPlayer::setActiveVideoTrack(int index)
+{
+    Q_D(QMediaPlayer);
+    if (d->control)
+        d->control->setActiveTrack(QPlatformMediaPlayer::VideoStream, index);
+}
+
+void QMediaPlayer::setActiveSubtitleTrack(int index)
+{
+    Q_D(QMediaPlayer);
+    if (d->control)
+        d->control->setActiveTrack(QPlatformMediaPlayer::SubtitleStream, index);
+}
+
 /*!
     Attach a video \a output to the media player.
 
diff --git a/src/multimedia/playback/qmediaplayer.h b/src/multimedia/playback/qmediaplayer.h
index 6df346e50..58f5201ce 100644
--- a/src/multimedia/playback/qmediaplayer.h
+++ b/src/multimedia/playback/qmediaplayer.h
@@ -123,19 +123,17 @@ public:
     bool setAudioOutput(const QAudioDeviceInfo &device);
     QAudioDeviceInfo audioOutput() const;
 
-//    using ContentStream = QVariantHash;
+    QList<QMediaMetaData> audioTracks() const;
+    QList<QMediaMetaData> videoTracks() const;
+    QList<QMediaMetaData> subtitleTracks() const;
 
-//    QList<ContentStream> audioStreams() const;
-//    QList<ContentStream> videoStreams() const;
-//    QList<ContentStream> subtitleStreams() const;
+    int activeAudioTrack() const;
+    int activeVideoTrack() const;
+    int activeSubtitleTrack() const;
 
-//    int audioStream() const;
-//    int videoStream() const;
-//    int subtitleStream() const;
-
-//    void setAudioStream(int index) const;
-//    void setVideoStream(int index) const;
-//    void setSubtitleStream(int index) const;
+    void setActiveAudioTrack(int index);
+    void setActiveVideoTrack(int index);
+    void setActiveSubtitleTrack(int index);
 
     void setVideoOutput(QObject *);
     void setVideoOutput(QAbstractVideoSurface *surface);
@@ -212,6 +210,9 @@ Q_SIGNALS:
 
     void metaDataChanged();
 
+    void tracksChanged();
+    void activeTracksChanged();
+
     void error(QMediaPlayer::Error error);
 
 private: