Phonon

    From KDE TechBase
    Revision as of 13:23, 10 May 2013 by Maidis (talk | contribs) (removed Tutorial Factbox: not very common at current tutorials. sections rearranged based on Hello World example)

    Introduction

    By getting involved with Phonon, you can choose between three different main tasks.

    • Using the Phonon API, which allows you to develop your own multimedia application. This is discussed here.
    • Hacking the Phonon library.
    • Writing Phonon backend, this consists in writing interfaces that allows Phonon to use different sound/video engine. This usually requires good skills and knowledge of the engine you interface with.

    Abstract

    The following example lets you select a music file and plays it. To change the sound device that is used by default, use the command systemsettings.

    The Code

    All the code we need will be in one file, main.cpp. Create that file with the code below:

    #include <phonon/mediaobject.h>
    #include <phonon/audiooutput.h>
    
    #include <QFileDialog>
    #include <QtGui/QApplication>
    #include <QtGui/QMainWindow>
    #include <QUrl>
    
    class MainWindow : public QMainWindow
    {
        Q_OBJECT
        public:
            MainWindow();
    };
    
    MainWindow::MainWindow()
    {
        Phonon::MediaObject* media = new Phonon::MediaObject(this);
        Phonon::createPath(media, new Phonon::AudioOutput(Phonon::MusicCategory, this));
        media->setCurrentSource(QFileDialog::getOpenFileName(0,QString("Select a file to play"),QString()));
        media->play();
    }
    
    int main(int argc, char **argv)
    {
        QApplication app(argc, argv);
        QApplication::setApplicationName("Phonon Tutorial 2");
        MainWindow mw;
        mw.show();
        return app.exec();
    }
    
    #include "main.moc"
    

    Build

    As usual, we use CMake for build operations:

    CMakeLists.txt

    You need a file CMakeLists.txt to compile the software:

    project (tutorial2)
    find_package(KDE4 REQUIRED)
    include (KDE4Defaults)
    include_directories(${KDE4_INCLUDES})
    set(tutorial1_SRCS main.cpp)
    kde4_add_executable(tutorial2 ${tutorial1_SRCS})
    target_link_libraries(tutorial2 ${KDE4_KDEUI_LIBS} phonon)
    install(TARGETS tutorial2  ${INSTALL_TARGETS_DEFAULT_ARGS})
    

    Make And Run

     cmake . && make && ./tutorial2
    

    Getting More Help

    To talk among phonon experts, point your irc client to the server irc.freenode.org, channel #phonon.

    See Also