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>

2 files changed, 62 insertions, 0 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;