Extracting video sequences into a new file

Hello,

I am trying to make a video/music player which let the user extract small sequences into a new file. First I am trying to understand how qt mutimedia works and how I could extract small sequences into a new file.
For instance I have a video inVideo.mp3 that last 200 secondes.
I want to extract the following intervals [4,10], [12,32] and [150,171] into a new video outVideo.mp2.
Anyeone know how I could do that?
Right now I tried that:
Here is my MainWindow.cpp.

[CODE]#include "MainWindow.h"
#include "ui_MainWindow.h"
#include <iostream>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
this->ui->setupUi(this);

QUrl urlInFile = QUrl::fromLocalFile("/home/cedric/VEG849.wmv");

this->playlist.addMedia(urlInFile);
this->player.setPlaylist(&playlist);

this->recorder = new QMediaRecorder(&player);
QVideoEncoderSettings videoEncoderSettings;
QAudioEncoderSettings audioEncoderSettings;

videoEncoderSettings.setCodec("video/mpeg2");
videoEncoderSettings.setResolution(640, 480);
audioEncoderSettings.setCodec("audio/vorbis");
audioEncoderSettings.setQuality(QtMultimediaKit::HighQuality);
this->recorder->setEncodingSettings(audioEncoderSettings, videoEncoderSettings);

QUrl urlOutFile = QUrl::fromLocalFile("/home/cedric/cuttedVideo.mp2");
this->recorder->setOutputLocation(urlOutFile);

this->connect(this->ui->startButton, SIGNAL(clicked()), this, SLOT(start()));
this->connect(this->ui->stopButton, SIGNAL(clicked()), this, SLOT(stop()));
//*/
}

MainWindow::~MainWindow()
{
delete ui;
delete this->recorder;
}

void MainWindow::start()
{
recorder->record();
player.play();
std::cout << "start" << std::endl;
//player.setPosition(2000);
}

void MainWindow::stop()
{
player.stop();
recorder->stop();
std::cout << "stop" << std::endl;
}
[/CODE]

I considere the other files not important but you can find them there:
[URL="http://code.google.com/p/testqtmobility/source/browse/#svn%2Ftrunk%2F04cutAudio"]http://code.google.com/p/testqtmobility/source/browse/#svn%2Ftrunk%2F04cutAudio[/URL]
The problem with that code is that the movie is playing and I can heard the sound. Also no new file is created.

Thanks in advance,

Cédric