Question

I’m developing on iOS SDK 4.3.
I have an horizontally-scrolling paged gallery that can display images or videos from a remote feed. For the paged views I’m using the publicly available ATPagingView: pages are reused similarly to TableViewCells. But for the videos I’m using a single MPMoviePlayerController, whose .view property I assign to the several pages as a subview (I know, I know…):

moviePlayerController = [[MPMoviePlayerController alloc] init];
moviePlayerController.repeatMode = MPMovieRepeatModeNone;
moviePlayerController.controlStyle = MPMovieControlStyleEmbedded;
moviePlayerController.shouldAutoplay = false;
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(movieLoadStateChangeAction:) name:MPMoviePlayerLoadStateDidChangeNotification object:nil];

You can see I’ve registered for MoviePlayer event LoadState notifications.
When a new page goes onscreen, I start loading a video if needed:

- (void)currentPageDidChangeInPagingView:(ATPagingView *)pagingView
{
if (pagingView.currentPageIndex < 0)
    return;

NSLog(@"currentPageDidChangeInPagingView");
GalleryPageView *currentPage = (GalleryPageView *)[pagingView viewForPageAtIndex:pagingView.currentPageIndex];
if (![currentPage.gestureRecognizers count]) {
    UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(resetZoom)];
    recognizer.numberOfTapsRequired = 2;
    [currentPage.zoomView addGestureRecognizer:recognizer];
    recognizer.delegate = self;
    [recognizer release];
}

moviePlayButton.hidden = YES;

[activityView stopAnimating];
FeedItem *feedItem = (FeedItem *)[dataRoot objectAtIndex:pagingView.currentPageIndex];
if (feedItem.contentType == FeedContentTypeMovie) {
    moviePlayerController.contentURL = [NSURL URLWithString:feedItem.movieUrl];
    [moviePlayerController prepareToPlay];
    [activityView startAnimating];
}

Now, IFF the first page contains a video, even after I call moviePlayerController.prepareToPlay, it doesn’t load: no loadState event is fired. Following pages instead work as expected.
I’ve tried to pre-load a fixed video on MPlayerController initialization, but in that case the fixed video is correctly loaded (MPMovieLoadState == 3), while video on first page causes a change to MPMovieLoadStateUnknown.

The movie URL is correct.
When I scroll back from page 2 to page 1, first video is loaded (MPMovieLoadState == 3), but it doesn’t show.

What do you suggest investigating? Is the shared-view architecture so horrible? It works for the following pages, after all. Is there any known weird behavior by prepareToPlay? For example, is it possible MPC gets angry if the view is “mistreated” by anyone, and then it refuses to load stuff? How else would you explain MPMovieLoadStateUnknown? I’m pretty sure there is no other ghost instance of MPC messing around (I’ve read it could be a problem).

Thank you and sorry for the long post.

Answer 1

I had to end up using AVPlayer because of something very similar to this in my code.