IPhone : MPMoviePlayerController view resizing brutally on iOS 8 but not on iOS 7

I have a MPMoviePlayerController willing to be display in fullscreen mode. It works fine on iOS 7 but the view (_moviePlayer.view) is resizing brutally on iOS 8 (the resize is smooth on iOS 7) and I have no clue why.



Here some usefull details :

- It's an iPad Landscape application

- self.imageButton.frame is here equal to (0, 96, 1024, 576)

- This code is in a method called from the viewDidAppear of a viewControlling managing the player (receiving the notifications, etc..)

_moviePlayer                        =  [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:self.model.filePath]];
_moviePlayer.controlStyle           = MPMovieControlStyleFullscreen;
_moviePlayer.view.backgroundColor   = [UIColor blackColor];

_moviePlayer.view.frame             = self.imageButton.frame;
[_moviePlayer prepareToPlay];
[self.view addSubview:_moviePlayer.view];

[_moviePlayer setFullscreen:YES animated:YES];