I have a 15 second animation in my app that is currently way too inefficient to be workable as it uses 1.5GB of RAM.
Am I using the animation properties of UIImageView incorrectly? Perhaps there is a different solution. All I want is for it to loop for a certain duration.
There will be improvements I can make to the 539 images to make them more efficient, but they still need to be retina size etc. Currently it is 30fps.
- (void)viewDidLoad {
[super viewDidLoad];
_animationFrames = [[NSMutableArray alloc] init];
for (long l = 0; l < 540; l++) {
NSString *frameNumber = [NSMutableString stringWithFormat:#"AnimationFrames-%04ld", l];
UIImage *frame = [UIImage imageNamed:frameNumber];
[_animationFrames addObject:frame];
}
UIImageView *animation = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
animation.animationImages = _tutorialFrames;
animation.animationDuration = 14;
[self.view addSubview: animation];
[animation startAnimating];
}
Thanks to Mirko Brunner's comments I discovered that I could use an embedded movie rather than play the animation through UIImageView, though I ended up going with AVPlayer rather than MPMoviePlayer.
#import "VideoViewController.h"
#import AVFoundation;
#interface VideoViewController ()
#property (weak, nonatomic) AVPlayer *avPlayer;
#property (weak, nonatomic) AVPlayerLayer *avPlayerLayer;
#end
#implementation VideoViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self avPlayer];
[self.avPlayer play];
}
- (AVPlayer *)avPlayer {
if (!_avPlayer) {
NSURL *url = [[NSBundle mainBundle]
URLForResource: #"Video" withExtension:#"mp4"];
_avPlayer = [AVPlayer playerWithURL:url];
_avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:_avPlayer];
_avPlayerLayer.frame = self.view.layer.bounds;
[self.view.layer addSublayer: _avPlayerLayer];
_avPlayer.actionAtItemEnd = AVPlayerActionAtItemEndNone;
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playerItemDidReachEnd:)
name:AVPlayerItemDidPlayToEndTimeNotification
object:[_avPlayer currentItem]];
}
return _avPlayer;
}
- (void)playerItemDidReachEnd:(NSNotification *)notification {
AVPlayerItem *p = [notification object];
[p seekToTime:kCMTimeZero];
}
Related
I'm writing Plugin for AVPlayer in ios. I need to know when user click on Done button in AVPlayerViewController ( I want to know when user close video) and I don't access to AVPlayerViewController object. I checked event and found only rate property in AVPlayer set to 0 but in pause situation also the rate set to 0 . how I figure out these two situations ?
thanks all.
I met the problem when I was developing the player in windowed mode. It is currently impossible without tricks. Therefore, I used KVO to observe contentOverlayView which is actually a full-size view of AVPlayerViewController. Code is a bit complicated. In the example below, playerView property is a view from xib/storyboard on the view controller (see attached).
#import <AVKit/AVKit.h>
#import <AVFoundation/AVFoundation.h>
static NSString * const kBoundsProperty = #"bounds";
static void * kBoundsContext = &kBoundsContext;
#interface ViewController ()
#property (nonatomic, strong) AVPlayerViewController *playerViewController;
// View for windowed mode.
#property (weak, nonatomic) IBOutlet UIView *playerView;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.playerViewController = [[AVPlayerViewController alloc] init];
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
// Because in -viewDidLoad frame is unknown.
[self loadPlayerView];
}
- (void)loadPlayerView {
NSURL *videoURL = [NSURL URLWithString:#"https://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4"];
AVPlayer *player = [[AVPlayer alloc] initWithURL:videoURL];
self.playerViewController.player = player;
[player play];
[self addChildViewController:self.playerViewController];
[self.playerView addSubview:self.playerViewController.view];
// MARK: I would recommend to use constraints instead of frame.
self.playerViewController.view.frame = self.playerView.bounds;
[self.playerViewController.contentOverlayView addObserver:self forKeyPath:kBoundsProperty options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:kBoundsContext];
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context {
if (context == kBoundsContext) {
CGRect oldBounds = [change[NSKeyValueChangeOldKey] CGRectValue];
CGRect newBounds = [change[NSKeyValueChangeNewKey] CGRectValue];
BOOL wasFullscreen = CGRectEqualToRect(oldBounds, [UIScreen mainScreen].bounds);
BOOL isFullscreen = CGRectEqualToRect(newBounds, [UIScreen mainScreen].bounds);
if (isFullscreen && !wasFullscreen) {
if (CGRectEqualToRect(oldBounds, CGRectMake(0.0, 0.0, newBounds.size.height, newBounds.size.width))) {
NSLog(#"Rotated fullscreen");
} else {
NSLog(#"Entered fullscreen");
dispatch_async(dispatch_get_main_queue(), ^{
[[NSNotificationCenter defaultCenter] postNotificationName:#"DidEnterInFullscreen" object:nil];
});
}
} else if (!isFullscreen && wasFullscreen) {
NSLog(#"Exited fullscreen");
dispatch_async(dispatch_get_main_queue(), ^{
[[NSNotificationCenter defaultCenter] postNotificationName:#"DidExitFromFullscreen" object:nil];
});
}
}
}
#end
I'm trying to use the library https://github.com/arturfelipet/AnimatedLogin
I created my own project and wrote exactly the same code as in their example (but in my project I used Storyboard), but the video only shows a black screen. Here's the way I create the MPMoviePlayerController:
#import <AVFoundation/AVFoundation.h>
#import <MediaPlayer/MediaPlayer.h>
#import <QuartzCore/QuartzCore.h>
#interface ViewController () {
MPMoviePlayerController *player;
}
#property (nonatomic, strong) MPMoviePlayerController *player;
#end
#implementation ViewController
#synthesize player;
- (void)viewDidLoad
{
[super viewDidLoad];
CGRect screen = [[UIScreen mainScreen] bounds];
NSURL *movieUrl = [[NSBundle mainBundle] URLForResource:#"background" withExtension:#"mp4"];
self.player = [[MPMoviePlayerController alloc] initWithContentURL:movieUrl];
player.view.frame = screen;
player.scalingMode = MPMovieScalingModeFill;
[self.player setControlStyle:MPMovieControlStyleNone];
[self.view addSubview:player.view];
[player prepareToPlay];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playVideo)
name:MPMoviePlayerReadyForDisplayDidChangeNotification
object:player];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(moviePlayerDidFinish:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:self.player];
[player play];
}
- (void)moviePlayerDidFinish:(NSNotification *)note
{
if (note.object == self.player) {
NSInteger reason = [[note.userInfo objectForKey:MPMoviePlayerPlaybackDidFinishReasonUserInfoKey] integerValue];
if (reason == MPMovieFinishReasonPlaybackEnded)
{
[self.player play];
}
}
}
-(void)playVideo{
[player play];
}
#end
But it's only a black screen when the app shows up. I'm using this code in my LoginViewController which presents from App Delegate like this:
if (![PFUser currentUser])
self.window.rootViewController = [UIStoryboard instansiateVCWithClass:[TPLoginViewController class]];
Maybe it has to do something with that? I've tried so many things and would really appreciate an answer.
Thanks.
That is because you doing all initializing in your viewDidLoad. Which means that processing will block your screen until all the task are done completely.
Put that code in a method and call it after delay using:
[self performSelector:<#(SEL)#> withObject:<#(id)#> afterDelay:<#(NSTimeInterval)#>];
EDIT: As turned out after checking with #tracifycray, there was some problem with URL,it was turning out nil somehow. As he said, "Yes, I got it to work. I tried to use a .mov-file instead, and then it worked".
I'm working on a IOS App (With Storyoard). I have a ViewController:
//movieViewController.h
#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>
#interface movieViewController : UIViewController {
MPMoviePlayerViewController *moviePlayer;
}
#property (strong, nonatomic) MPMoviePlayerViewController *moviePlayer;
-(void) playMovie;
#end
//movieViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
[self playMovie];
}
-(void)playMovie
{
NSString *videoPath = [[NSBundle mainBundle] pathForResource:#"movie"
ofType:#"mov"];
moviePlayer = [[MPMoviePlayerViewController alloc] initWithContentURL:[NSURL
fileURLWithPath:videoPath]];
[self presentMoviePlayerViewControllerAnimated:moviePlayer];
}
When I run I see my viewController with a "Loading..." that takes forever.
You should call -prepareToPlay and/or -play. Per MPMoviePlayerController's documentation:
Starting in iOS 5.0, in order to facilitate finer-grained playback control, a new movie player is not automatically prepared to play.
-(IBAction)startVideo:(id)sender
{
NSURL *video = [[NSURL alloc] initWithString:#"http://www.w3schools.com/html/movie.mp4"];
MPMoviePlayerViewController *controller = [[MPMoviePlayerViewController alloc]initWithContentURL:video];
controller.view.frame = CGRectMake(20, 50, 280, 180);
controller.moviePlayer.view.center = self.view.center;
[self.view addSubview:controller.view];
[controller.moviePlayer prepareToPlay];
[controller.moviePlayer play];
}
I´m trying to use UITapGestureRecognizer in order to handle the taps on my fullscreen video. If I omit [self.player setFullscreen:YES animated:NO]; it works, but then my video won't scale to fit the screen.
From my .m:
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *videoPath = [[NSBundle mainBundle] pathForResource:#"test" ofType:#"mov"];
player = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:videoPath]];
player.shouldAutoplay = NO;
player.view.frame = self.view.bounds;
player.scalingMode = MPMovieScalingModeAspectFit;
player.controlStyle = MPMovieControlStyleNone;
player.fullscreen = YES;
self.player = player;
[self.player prepareToPlay];
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
UIView *aView = [[UIView alloc] initWithFrame:player.view.bounds];
[aView addGestureRecognizer:tapGesture];
[self.player.view addSubview:aView];
}
- (IBAction)playMovie:(id)sender {
//add the MPMoviePlayerViewController to this view (as subview)
//Play movie
[self.view addSubview:self.player.view];
[self.player setFullscreen:YES animated:NO]; //commenting out this will make it work
[self.player play];
}
- (void)handleTap:(UITapGestureRecognizer *)recognizer {
NSLog(#"tap tap");
}
From my .h:
#property (retain, nonatomic) MPMoviePlayerController *player;
- (void)handleTap:(UITapGestureRecognizer *)recognizer;
You can try this:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(willEnterFullScreen:)
name:MPMoviePlayerWillEnterFullscreenNotification
object:nil];
- (void)willEnterFullScreen:(NSNotification*)notification
{
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
UIView *aView = [[UIView alloc] initWithFrame:self.player.backgroundView.bounds];
[aView addGestureRecognizer:tapGesture];
[self.view.window addSubview:aView];
}
and then remove your subview when MPMoviePlayerWillExitFullscreenNotification is posted
In my comment, I drafted how to get that covered when using proper fullscreen ([self.player setFullscreen:YES animated:NO];).
I would suggest that instead you simply resize the player view to cover the entire screen by setting its frame accordingly.
You initialising code would have to get rid of that player.fullscreen = YES;, but that I guess is obvious by now.
I am working on an app that will let me play different videos on the iPad remotely with an iPhone. I have been following along with apples example for a video player but I've been having some troubles. The videos play just fine and I can get it to play from a variety of videos but switching between them a few times it will crash and i get this in the debugger:
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'An AVPlayerItem cannot be associated with more than one instance of AVPlayer'
*** First throw call stack:
(0x380da8bf 0x37c261e5 0x30acbcb5 0x30abc1f7 0x30ac3bf3 0x30c93d55 0x30c95f7b 0x380ad2dd 0x380304dd 0x380303a5 0x37e07fcd 0x31bb0743 0x25e5 0x257c)
This is the code I am using to create the player:
MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentOfURL:movieURL];
if (player) {
[self setMoviePlayerController:player];
[self installMovieNotificationObservers];
[player setContentURL:movieURL];
[player setMovieSourceType:sourceType];
[self applyUserSettingsToMoviePlayer];
[self.view addSubview:self.backgroundView];
[player.view setFrame:self.view.bounds];
[player.view setBackgroundColor = [UIColor blackColor];
[self.view addSubview:player.view];
}
And when the current movie is stopped I use:
[[self moviePlayerController] stop];
MPMoviePlayerController *player = [self moviePlayerController];
[player.view removeFromSuperview];
[self removeMovieNotificationHandlers];
[self setMoviePlayerController:nil];
Edit:
So Ive now discovered it happens every time i try and switch a video for the 11th time. weird! I'm practically pulling my hair out.
What fixed this problem for me was stopping the MPMoviePlayerController before doing the setContentURL.
MPMoviePlayerController *streamPlayer;
[streamPlayer stop];
[streamPlayer setContentURL:[NSURL URLWithString:selectedStation]];
In the implementation you have above, ARC doesn't know that the MPMoviePlayerController is finished and needs to be released.
Define MPMoviePlayerController in your .h file and make it accessible via a #property (and #synthesize).
#property (strong, nonatomic) MPMoviePlayerController * moviePlayerController;
Then take the result of your alloc & init and assign it to that. I.E.
self.moviePlayerController = [[MPMoviePlayerController alloc] initWithContentOfURL:movieURL];
you should just keep the moviePlayerController and if you want to play another video, just use
[self.moviePlayerController setContentURL:movieURL];
then in your notification callback:
- (void) moviePlayBackDidFinish:(NSNotification*)notification
{
self.moviePlayer = nil;
[self initanothermovieplayerandplay];
}
and please do not remove the notification handler from notification center, only do this in dealloc method of your VC.
now let's add some fade when the movie play is done:
- (void) moviePlayBackDidFinish:(NSNotification*)notification
{
[UIView animateWithDuration:1
delay: 0.0
options: UIViewAnimationOptionCurveEaseIn
animations:^{
// one second to fade out the view
self.moviePlayer.view.alpha = 0.0;
}
completion:^(BOOL finished){
self.moviePlayer = nil;
[self initanothermovieplayerandplay];
}
}
I had exactly the same problem.
Nothing was wrong with my and i guess with your code :)
Just a broken video file was mine problem.
Changing *.mov type to m4a for example fixed it. Maybe one or more of the files you play are corrupted?
Try to find out which files lead to crash and than if u can try to quickly forward backward the play position of one of them while playing - this should lead to crash in few tries.
This is how i found the bad files. By the way all my bad files were movies .mov made with Snapz Pro X :)
Not sure if it is the case here, but we had a lot of problems, because the MPMoviePlayer is a singleton somewhere under the hood.
What we did is, that we implemented our own MoviePlayer wrapper which can be used from UIView (actually we have exactly one subclass of UIView MoviePlayerView to show movies) and assures that only one instance of MPMoviePlayerController exists. The code goes like this (it contains some special stuff, we need to show previews/thumbs the way we want etc. you should clean up as well as some release-statements):
// MoviePlayer.h
#import <Foundation/Foundation.h>
#import <MediaPlayer/MediaPlayer.h>
#import "Logger.h"
#class MoviePlayerView;
#interface MoviePlayer : NSObject
{
#private
MPMoviePlayerController *controller;
MoviePlayerView *currentView;
}
#property (nonatomic, readonly) MPMoviePlayerController *controller;
+(MoviePlayer *) instance;
-(void) playMovie:(NSURL*)movieURL onView:(MoviePlayerView *)view;
-(void) stopMovie;
#end
// MoviePlayer.m
#import "MoviePlayer.h"
#import "MoviePlayerView.h"
#implementation MoviePlayer
#synthesize controller;
static MoviePlayer *player = nil;
#pragma mark Singleton management
+(MoviePlayer *) instance
{
#synchronized([MoviePlayer class])
{
if (player == nil)
{
player = [[super allocWithZone:NULL] init];
player->controller = [[MPMoviePlayerController alloc] init];
player->controller.shouldAutoplay = NO;
player->controller.scalingMode = MPMovieScalingModeAspectFit;
player->currentView = nil;
}
return player;
}
}
+(id) allocWithZone:(NSZone *)zone
{
return [[self instance] retain];
}
-(id) copyWithZone:(NSZone *)zone
{
return self;
}
-(id) retain
{
return self;
}
-(NSUInteger) retainCount
{
return NSUIntegerMax;
}
-(oneway void) release
{
// singleton will never be released
}
-(id) autorelease
{
return self;
}
#pragma mark MoviePlayer implementations
-(void) stopMovie
{
#synchronized(self)
{
if (controller.view.superview)
{
[controller.view removeFromSuperview];
}
if (controller.playbackState != MPMoviePlaybackStateStopped)
{
[controller pause];
[controller stop];
}
if (currentView)
{
NSNotificationCenter *ntfc = [NSNotificationCenter defaultCenter];
[ntfc removeObserver:currentView name:MPMoviePlayerLoadStateDidChangeNotification object:controller];
[ntfc removeObserver:currentView name:MPMoviePlayerPlaybackStateDidChangeNotification object:controller];
currentView = nil;
}
}
}
-(void) playMovie:(NSURL*)movieURL onView:(MoviePlayerView *)view
{
#synchronized(self)
{
[self stopMovie];
currentView = view;
NSNotificationCenter *ntfc = [NSNotificationCenter defaultCenter];
[ntfc addObserver:currentView
selector:#selector(loadStateDidChange:)
name:MPMoviePlayerLoadStateDidChangeNotification
object:controller];
[ntfc addObserver:currentView
selector:#selector(playbackStateDidChange:)
name:MPMoviePlayerPlaybackStateDidChangeNotification
object:controller];
[controller setContentURL:movieURL];
controller.view.frame = view.bounds;
[view addSubview: controller.view];
[controller play];
}
}
#end
// MoviePlayerView.h
#import <UIKit/UIKit.h>
#import "MoviePlayer.h"
#interface MoviePlayerView : MediaView
{
NSURL *movieURL;
NSURL *thumbnailURL;
UIImageView *previewImage;
UIView *iconView;
BOOL hasPreviewImage;
}
-(id) initWithFrame:(CGRect)frame thumbnailURL:(NSURL *)thumbnail movieURL:(NSURL *)movie;
-(void) loadStateDidChange:(NSNotification *)ntf;
-(void) playbackStateDidChange:(NSNotification *)ntf;
#end
// MoviePlayerView.m
#import "MoviePlayerView.h"
#interface MoviePlayerView()
-(void) initView;
-(void) initController;
-(void) playMovie;
-(void) setActivityIcon;
-(void) setMovieIcon:(float)alpha;
-(void) clearIcon;
-(CGPoint) centerPoint;
#end
#implementation MoviePlayerView
-(id) initWithFrame:(CGRect)frame thumbnailURL:(NSURL *)thumbnail movieURL:(NSURL *)movie
{
self = [super initWithFrame:frame];
if (self)
{
movieURL = [movie retain];
thumbnailURL = [thumbnail retain];
[self initView];
[self initController];
hasPreviewImage = NO;
loadingFinished = YES;
}
return self;
}
-(void) dealloc
{
[iconView release];
[previewImage release];
[movieURL release];
[super dealloc];
}
-(void)initView
{
self.backgroundColor = [UIColor blackColor];
// add preview image view and icon view
previewImage = [[UIImageView alloc] initWithFrame:self.bounds];
[previewImage setContentMode:UIViewContentModeScaleAspectFit];
UIImage *img = nil;
if (thumbnailURL)
{
img = [ImageUtils loadImageFromURL:thumbnailURL];
if (img)
{
previewImage.image = img;
hasPreviewImage = YES;
}
}
[self addSubview:previewImage];
[self setMovieIcon:(hasPreviewImage ? 0.8f : 0.3f)];
}
-(void)initController
{
UITapGestureRecognizer *rec = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(playMovie)];
[self addGestureRecognizer:rec];
[rec release];
}
-(void)playMovie
{
[[MoviePlayer instance] playMovie:movieURL onView:self];
[self setActivityIcon];
}
-(void) loadStateDidChange:(NSNotification *)ntf
{
MPMoviePlayerController *controller = [ntf object];
switch (controller.loadState)
{
case MPMovieLoadStatePlayable:
{
[self clearIcon];
[controller setFullscreen:YES animated:YES];
break;
}
case MPMovieLoadStateStalled:
{
[self setActivityIcon];
break;
}
default:
{
break; // nothing to be done
}
}
}
-(void) playbackStateDidChange:(NSNotification *)ntf
{
MPMoviePlayerController *controller = [ntf object];
switch (controller.playbackState)
{
case MPMoviePlaybackStatePlaying:
{
[self clearIcon];
break;
}
case MPMoviePlaybackStateStopped:
{
[self setMovieIcon:(hasPreviewImage ? 0.8f : 0.3f)];
break;
}
case MPMoviePlaybackStatePaused:
{
[self setMovieIcon:0.8f];
break;
}
case MPMoviePlaybackStateInterrupted:
{
[self setActivityIcon];
break;
}
default:
{
break; // nothing to be done
}
}
}
-(void) setActivityIcon
{
[self clearIcon];
iconView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
iconView.center = [self centerPoint];
[self addSubview:iconView];
[iconView performSelector:#selector(startAnimating)];
}
-(void) setMovieIcon:(float)alpha
{
[self clearIcon];
iconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"icon_movie.png"]];
iconView.center = [self centerPoint];
iconView.alpha = alpha;
[self addSubview:iconView];
}
-(void) clearIcon
{
if (iconView)
{
SEL stop = #selector(stopAnimating);
if ([iconView respondsToSelector:stop])
{
[iconView performSelector:stop];
}
[iconView removeFromSuperview];
[iconView release];
iconView = nil;
}
}
-(CGPoint) centerPoint
{
return CGPointMake(roundf(self.bounds.size.width / 2.0f), roundf(self.bounds.size.height / 2.0f));
}
-(void)resize
{
for (UIView *view in [self subviews])
{
if (view == iconView)
{
iconView.center = [self centerPoint];
continue;
}
view.frame = self.bounds;
}
[self addCaptionLabel];
}
-(void) layoutSubviews
{
[super layoutSubviews];
[self resize];
}
#end
...
player = [[MPMoviePlayerController alloc] initWithContentURL: [NSURL URLWithString:...
...
but I didn't gave internet connection to phone (wi-fi) :)
I had the same problem. My solution is using prepareToPlay:
MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentOfURL:movieURL];
if (player) {
[player prepareToPlay];
//...
}
This error seems to be thrown for lots of different reasons, but the reason I found was that the MPMoviePlayerController class freaks out if you call methods in a certain order. From an IRC Channel:
"apparently if you call prepareToPlay WHILE setting source type and
NOT setting the view yet causes this crash"
So I fixed this by just making sure that I called prepareToPlay: LAST (or second to last, with the last being play:).
It is also weird because my original code worked in iOS 5.1, but this problem suddenly manifested when I started using the iOS 6.0 sdk. It is possibly a bug in the MPMoviePlayerController code, so I'm going to be filing a radar report on it, as calling prepareToPlay: before setting the view / setting the sourceFileType should not throw an exception (or at least an exception that seemingly has nothing to do with the actual error)