Phonon

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Revision as of 13:58, 15 August 2010 by Tstaerk (talk | contribs) (I don't have an idea what that is. Most people will not.)

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.

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 lets you choose a multimedia file and tries to play 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:

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);
    Phonon::AudioOutput *audioOutput = new Phonon::AudioOutput(Phonon::MusicCategory, this);
    createPath(media, audioOutput);
    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