Phonon: Difference between revisions

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    These tutorials are now under construction, please be patient.
    = Introduction =
    This document has born the 28th of February 2007.
    By getting involved with Phonon, you can choose between three different main tasks.
    In order to make the revision process clear, I introduce a confident index, 0 means that nobody except me had reviews the text. I please the reviewers to increment the counter to prove the validity of the tutorials.
    * '''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.


    If you are a Phonon developer and you realize errors, you're missing some details or a whole chapter. Please feel free to complete the followings.
    =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>.


    ----
    =The Code=
    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/audiooutput.h>


    =Introduction=
    #include <QFileDialog>
    The following is based on the documentation available here.
    #include <QtGui/QApplication>
    [http://www.englishbreakfastnetwork.org/apidocs/apidox-kde-4.0/kdelibs-apidocs/phonon/html/index.html Phonon API].
    #include <QtGui/QMainWindow>
    #include <QUrl>


    Getting involved with Phonon consists in three different main tasks.
    class MainWindow : public QMainWindow
    * '''Using the Phonon API''', which allows you to develop your own multimedia application.
    {
        Q_OBJECT
        public:
            MainWindow();
    };


    * '''Hacking the Phonon library''', (try to develop more this topic).
    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();
    }


    * '''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.
    int main(int argc, char **argv)
    {
        QApplication app(argc, argv);
        QApplication::setApplicationName("Phonon Tutorial 2");
        MainWindow mw;
        mw.show();
        return app.exec();
    }


    By the way the beginners will probably be interested by the first task.
    #include "main.moc"
    </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>


    [[Category:KDE4]]
    ==Make And Run==
    [[Category:Phonon]]
    <syntaxhighlight lang="bash">
    cmake . && make && ./phonon_tutorial1
    </syntaxhighlight>
     
    = Getting More Help =
    To talk among phonon experts, point your irc client to the server irc.freenode.org, channel #phonon.
     
    = See Also =
    * [[/Python]] - same example in Python

    Revision as of 19:20, 11 March 2016

    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