QMediaPlaylist - display image with custom timeout / elapsed time

[darbor]

Hello
I work on QT5.2.1 (windows 8.1)
I try create simple slider to video and images

@

playlist = new QMediaPlaylist;
player = new QMediaPlayer;
videoWidget = new QVideoWidget;

playlist->addMedia(QUrl("video1.mp4")); // duration 15secound
playlist->addMedia(QUrl("image1.jpg")); // I would like 10 seconds
playlist->addMedia(QUrl("video2.mp4")); // duration 20secound
playlist->addMedia(QUrl("image2.jpg")); // I would like 10 seconds

playlist->setPlaybackMode(QMediaPlaylist::Loop);
player->setPlaylist(playlist);
player->setVideoOutput(videoWidget);
player->play();

@

When i run this program i see video1.mp4 (15 secound) after i see image1.jpg but only 0.5secound and after
video2.mp4 (20 secound) and image2.jpg (only 0.5secound)

How can i set custom duration for image1.jpg and image2.jpg??