Phonon: Difference between revisions

    From KDE TechBase
    (21 intermediate revisions by 2 users not shown)
    Line 1: Line 1:
    In order to make the revision process clear, I introduce a confident index, "0" means nobody except me has reviewed the text. I please the reviewers to increment the counter to prove the validity of the tutorials.
    {{Infobox tutorial|time=20 min|distribution=SUSE Linux 11.4|type=Howto|happyreaders=2|unhappyreaders=0}}
     
    You can get help on #phonon on irc.freenode.org.
    ----
     
    See [[Development/Tutorials/Phonon/Introduction/Python]] for the same example in Python.


    = Introduction =
    = Introduction =
    The following is based on the documentation available here
    [http://www.englishbreakfastnetwork.org/apidocs/apidox-kde-4.0/kdelibs-apidocs/phonon/html/index.html Phonon API].
    By getting involved with Phonon, you can choose between three different main tasks.
    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.  
    * '''Using the Phonon API''', which allows you to develop your own multimedia application. '''This is discussed here.'''


    * '''Hacking the Phonon library''', (try to develop more this topic).
    * '''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.
    * '''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 =
    = 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 <tt>systemsettings</tt>.
    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 <tt>systemsettings</tt>.


    == CMakeLists.txt ==
    == CMakeLists.txt ==
    You need a file CMakeLists.txt to compile the software later:
    You need a file CMakeLists.txt to compile the software later:
    CMakeLists.txt
      project (tutorial2)
      project (tutorial2)
      find_package(KDE4 REQUIRED)
      find_package(KDE4 REQUIRED)
      include (KDE4Defaults)
      include (KDE4Defaults)
      include_directories(${KDE4_INCLUDES})
      include_directories(${KDE4_INCLUDES})
      set(tutorial1_SRCS tutorial2.cpp)
      set(tutorial1_SRCS main.cpp)
      kde4_add_executable(tutorial2 ${tutorial1_SRCS})
      kde4_add_executable(tutorial2 ${tutorial1_SRCS})
      target_link_libraries(tutorial2 ${KDE4_KDEUI_LIBS} phonon)
      target_link_libraries(tutorial2 ${KDE4_KDEUI_LIBS} phonon)
      install(TARGETS tutorial2  ${INSTALL_TARGETS_DEFAULT_ARGS})
      install(TARGETS tutorial2  ${INSTALL_TARGETS_DEFAULT_ARGS})


    == tutorial2.cpp ==
    == main.cpp ==
    <pre>
    <pre>
    #include <phonon/mediaobject.h>
    #include <phonon/mediaobject.h>
    #include <phonon/audiooutput.h>
    #include <phonon/audiooutput.h>


    #include <QFileDialog>
    #include <QtGui/QApplication>
    #include <QtGui/QApplication>
    #include <QtGui/QMainWindow>
    #include <QtGui/QMainWindow>
    Line 53: Line 43:
    {
    {
         Phonon::MediaObject* media = new Phonon::MediaObject(this);
         Phonon::MediaObject* media = new Phonon::MediaObject(this);
         Phonon::AudioOutput *audioOutput = new Phonon::AudioOutput(Phonon::MusicCategory, this);
         Phonon::createPath(media, new Phonon::AudioOutput(Phonon::MusicCategory, this));
        createPath(media, audioOutput);
         media->setCurrentSource(QFileDialog::getOpenFileName(0,QString("Select a file to play"),QString()));
         media->setCurrentSource(QUrl("/tmp/example.wav"));
         media->play();
         media->play();
    }
    }
    Line 68: Line 57:
    }
    }


    #include "tutorial2.moc"
    #include "main.moc"
    </pre>
    </pre>


    == Compile and run it ==
    == Compile and run it ==
      cmake . && make && ./tutorial2
      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 =
    * [[Development/Tutorials/Phonon/Introduction/Python]] - same example in Python


    [[Category:KDE4]]
    [[Category:KDE4]]
    [[Category:Phonon]]
    [[Category:Phonon]]
    [[Category:Tutorial]]

    Revision as of 08:33, 26 September 2011


    Tutorial Factbox
    Time to replay 20 min
    Example Distro SUSE Linux 11.4
    Type Howto
    Happy readers 2
    Unhappy readers 0

    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.

    Using the phonon API

    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.

    CMakeLists.txt

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

    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})
    

    main.cpp

    #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"
    

    Compile and run it

    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