iOS - MPMoviePlayerController resets view transform on repeat - ios

Question

Using an MPMoviePlayerController.view as a background (think spotify). A user can tap login or signup and they are taken to the appropriate viewController, which has a clear background so that the moviePlayer.view remains as the background (i.e., user continues to see the video regardless of the currently active viewController) throughout the flow.
On some viewControllers the form needs to be lifted up so that the keyboard doesn't cover the field. I'm doing this using a transform.
The background video of the moviePlayer is set to repeat, so the video is on a continuous loop. Each time the video resets (video status goes from 1 to 2 - paused to playing) the transform resets in the child viewControllers. My initial thought was that the view was being redrawn, but this doesn't appear to be the case based on logs (I put nslogs in the drawRect of the views but it's only ever called once at instantiation).
Has anyone come across this?
My setup in the root viewController:
// lazy load moviePlayer
-(MPMoviePlayerController *)moviePlayer
{
if (_moviePlayer) return _moviePlayer;
NSURL *videoURL = [[NSBundle mainBundle] URLForResource:#"resources.bundle/videos/auth_bg" withExtension:#"mp4"];
_moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:videoURL];
_moviePlayer.controlStyle = MPMovieControlStyleNone;
_moviePlayer.scalingMode = MPMovieScalingModeAspectFill;
_moviePlayer.repeatMode = MPMovieRepeatModeOne;
_moviePlayer.shouldAutoplay = true;
return _moviePlayer;
}
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
self.moviePlayer.view.frame = self.view.frame;
self.moviePlayer.view.hidden = false;
// 'still' is an imageView of the first frame to show while video loading
[self.navigationController.view insertSubview:self.moviePlayer.view aboveSubview:still];
}

Answer 1

I suspect this has to do with Autolayout -- I found a few other questions where views were being reset (one example here: https://stackoverflow.com/a/17849584/1542275) ... My solution was to adjust the layout constraint constants as opposed to transforming the view coordinates. Things are now staying put.
All of that said, I'm still not sure why the video restart is resetting the transforms.