Tutorial: Simple Media Player

Files:

• simpleplayer/basicmedia.cpp
• simpleplayer/basicmedia.h
• simpleplayer/simpleplayer.cpp
• simpleplayer/simpleplayer.h
• simpleplayer/simpleplayerbase.ui
• simpleplayer/main.cpp
• simpleplayer/qbuild.pro

The Simple Media Player application tutorial shows how to use the Qt Extended Media API to create a simple Media player application. It also demonstrates using a QDocumentSelectorDialog to get audio/video selections from the document system.

The Simple Player application displays a list of audio/video files. When a file is selected the the Media API is called and the media is played.

Firstly a container for all player objects is created.

    context = new QMediaContentContext(this);

Then a watch is added for media control.

    controlNotifier = new QMediaControlNotifier(QMediaControl::name(), this);
    connect(controlNotifier, SIGNAL(valid()), this, SLOT(mediaControlValid()));
    context->addObject(controlNotifier);

Then a watch is added for the video as well.

    videoNotifier = new QMediaControlNotifier(QMediaVideoControl::name(), this);
    connect(videoNotifier, SIGNAL(valid()), this, SLOT(mediaVideoControlValid()));
    context->addObject(videoNotifier);

Once you have a file to play.

    QContent content(filename);
    m_mediaContent = new QMediaContent(content);
    context->setMediaContent(m_mediaContent);

The Media API will emit the valid signal that you have attached to mediaControlValid()

    m_control = new QMediaControl(m_mediaContent);
    m_control->start();

If it has video it will then emit the valid signal you have attached to mediaVideoControlValid()

    m_video = new QMediaVideoControl(m_mediaContent);
    videoWidget = m_video->createVideoWidget(this);
    videoWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    layout->addWidget(videoWidget);

    class BasicMedia : public QWidget
    {
    Q_OBJECT

    public:
        BasicMedia(QWidget* parent);
        ~BasicMedia();

        void stop();
        void start();
        void setFilename(QString filename);
        void volumeup();
        void volumedown();

    protected:
        void keyReleaseEvent( QKeyEvent * );

    private:
        QMediaContentContext* context;
        QMediaContent*        m_mediaContent;
        QMediaControl*        m_control;
        QMediaVideoControl*   m_video;

        int  m_state;
        int  volume;

    private slots:
        void mediaVideoControlValid();
        void mediaControlValid();

    private:
        QWidget*     videoWidget;
        QString      vfile;
        QVBoxLayout* layout;
    };