Phonon

    From KDE TechBase
    Revision as of 02:28, 18 September 2010 by Tstaerk (talk | contribs)

    Tutorial Factbox
    Time to replay 20 min
    Example Distro SUSE Linux 11.3
    Type {{{type}}}
    Happy readers {{{happyreaders}}}
    Unhappy readers {{{unhappyreaders}}}

    You can get help on #phonon on irc.freenode.org.


    See Development/Tutorials/Phonon/Introduction/Python for the same example in Python.

    Introduction

    The following is based on the documentation available here Phonon API.

    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. In fact any application which needs sound can take benefits from the phonon API. In the tutorials showing the API we will learn how to set up the development environment with kdevelop 3.4.
    • Hacking the Phonon library, (try to develop more this topic).
    • 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.

    Beginners will probably be more interested by the first task.

    Using the phonon API

    The following example is taken from http://www.englishbreakfastnetwork.org/apidocs/apidox-kde-4.0/kdelibs-apidocs/phonon/html/index.html. It plays /tmp/example.wav. To change the sound device that is used by default, use the command systemsettings.

    CMakeLists.txt

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

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

    tutorial2.cpp

    #include <phonon/mediaobject.h>
    #include <phonon/audiooutput.h>
    
    #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);
        createPath(media, new Phonon::AudioOutput(Phonon::MusicCategory, this));
        media->setCurrentSource(QUrl("/tmp/example.wav"));
        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 "tutorial2.moc"
    

    Compile and run it

    cmake . && make && ./tutorial2