Phonon: Difference between revisions

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    {{Infobox tutorial|time=20 min|distribution=SUSE Linux 11.3|type=Howto|happyreaders=2|unhappyreaders=0}}
    = 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.
    * '''Using the Phonon API''', which allows you to develop your own multimedia application. '''This is discussed here.'''
     
    * '''Hacking the Phonon library'''.
    * '''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.
    =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 <tt>systemsettings</tt>.
    = 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 englishbreakfastnetwork]. It plays /tmp/example.wav. To change the sound device that is used by default, use the command <tt>systemsettings</tt>.
     
    == 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 ==
    =The Code=
    <pre>
    All the code we need will be in one file, <tt>main.cpp</tt>. Create that file with the code below:
    <syntaxhighlight lang="cpp-qt">
    #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 48: Line 29:
    {
    {
         Phonon::MediaObject* media = new Phonon::MediaObject(this);
         Phonon::MediaObject* media = new Phonon::MediaObject(this);
         createPath(media, new Phonon::AudioOutput(Phonon::MusicCategory, this));
         Phonon::createPath(media, new Phonon::AudioOutput(Phonon::MusicCategory, this));
         media->setCurrentSource(QUrl("/tmp/example.wav"));
         media->setCurrentSource(QUrl::fromLocalFile(QFileDialog::getOpenFileName(0,QString("Select a file to play"),QString())));
         media->play();
         media->play();
    }
    }
    Line 62: Line 43:
    }
    }


    #include "tutorial2.moc"
    #include "main.moc"
    </pre>
    </syntaxhighlight>
     
    =Build=
    As usual, we use CMake for build operations:
     
    == CMakeLists.txt ==
    You need a file CMakeLists.txt to compile the software:
    <syntaxhighlight lang="cmake">
    project (phonon_tutorial1)
    find_package(KDE4 REQUIRED)
    include (KDE4Defaults)
    include_directories(${KDE4_INCLUDES})
    set(phonon_tutorial1_SRCS main.cpp)
    kde4_add_executable(phonon_tutorial1 ${phonon_tutorial1_SRCS})
    target_link_libraries(phonon_tutorial1 ${KDE4_KDEUI_LIBS} ${PHONON_LIBS})
    install(TARGETS phonon_tutorial1  ${INSTALL_TARGETS_DEFAULT_ARGS})
    </syntaxhighlight>


    == Compile and run it ==
    ==Make And Run==
    cmake . && make && ./tutorial2
    <syntaxhighlight lang="bash">
    cmake . && make && ./phonon_tutorial1
    </syntaxhighlight>


    = Getting more help =
    = Getting More Help =
    To talk among phonon experts, point your irc client to the server irc.freenode.org, channel #phonon.
    To talk among phonon experts, point your irc client to the server irc.freenode.org, channel #phonon.


    = See also =
    = See Also =
    * [[Development/Tutorials/Phonon/Introduction/Python]] - same example in Python
    * [[Development/Tutorials/Phonon/Introduction/Python]] - same example in Python



    Revision as of 22:46, 23 August 2013

    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(QUrl::fromLocalFile(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 (phonon_tutorial1)
    find_package(KDE4 REQUIRED)
    include (KDE4Defaults)
    include_directories(${KDE4_INCLUDES})
    set(phonon_tutorial1_SRCS main.cpp)
    kde4_add_executable(phonon_tutorial1 ${phonon_tutorial1_SRCS})
    target_link_libraries(phonon_tutorial1 ${KDE4_KDEUI_LIBS} ${PHONON_LIBS})
    install(TARGETS phonon_tutorial1  ${INSTALL_TARGETS_DEFAULT_ARGS})
    

    Make And Run

    cmake . && make && ./phonon_tutorial1
    

    Getting More Help

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

    See Also