I’ve been troubleshooting a project that animates 24 different sets of png images. Each set containing around 30 images. The App would eventually crash when run on an iPad after running through about half a dozen of the animations. Eventually running into a memory limit. In my search for solutions, I ran into Mo DeJong’s PNGAnimatorDemo, which completely solved the memory limit problem.

The example project he provides runs the animation full frame by default so I had to modify some things in order to add it as a subview to another view and to set it inside a CGRect.

The first thing to be done was to create a new property ‘viewCGRect’ with which I could set a CGRect for the ImageAnimatorViewController . I also took out the animationOrientation property and associated code since this is now being added as a subVIew to another view.

- (void)loadView { 
// UIView *myView = [[UIView alloc] initWithFrame:[UIScreen mainScreen].applicationFrame]; 
UIView *myView = [[UIView alloc] initWithFrame:viewCGRect]; 
myView autorelease]; 
self.view = myView; 

// FIXME: Additional Supported Orientations 
if (animationOrientation == UIImageOrientationUp) { 
    // No-op 
} else if (animationOrientation == UIImageOrientationLeft) { 
    // 90 deg CCW [self rotateToLandscape]; 
} else if (animationOrientation == UIImageOrientationRight) { 
    // 90 deg CW [self rotateToLandscapeRight]; 
} else { 
    NSAssert(FALSE,@"Unsupported animationOrientation"); 
}

Then inside my superViewController I modified the startAnimator method in order to pass a different file name prefix for every animation. As well as a specific length (each animation had varying lengths) and a CGRect with which to draw the animation.

- (void) startAnimator:(NSString *) pref endingWith: (int) end andFrame:(CGRect) rect { 
//[viewController.view removeFromSuperview]; 

self.animatorViewController = [ImageAnimatorViewController imageAnimatorViewController]; 

NSArray *names = [ImageAnimatorViewController arrayWithNumberedNames:pref 
rangeStart:1 
rangeEnd:end 
suffixFormat:@"%02i.png"]; 

NSArray *URLs = [ImageAnimatorViewController arrayWithResourcePrefixedURLs:names]; 

// setting the public property for our custom CGRect: 

animatorViewController.viewCGRect = rect; 

// we no longer need to provide an orientation //animatorViewController.animationOrientation = UIImageOrientationUp; // Rotate 90 deg CCW 
animatorViewController.animationFrameDuration = ImageAnimator15FPS; 
animatorViewController.animationURLs = URLs; 
animatorViewController.animationRepeatCount = 0; 

// Show animator before starting animation 

// add the animatorViewController.view as a subView: 
[self.view addSubview:animatorViewController.view]; 

[[NSNotificationCenter defaultCenter] addObserver:self 
selector:@selector(animationDidStartNotification:) 
name:ImageAnimatorDidStartNotification 
object:animatorViewController]; 

[[NSNotificationCenter defaultCenter] addObserver:self 
selector:@selector(animationDidStopNotification:) 
name:ImageAnimatorDidStopNotification 
object:animatorViewController]; 

[animatorViewController startAnimating]; }

Then lastly I commented out parts of the stopAnimator method so that the final frame of each animation would remain until I needed to dispose of it by using another method clearAnimation. 

- (void) stopAnimator { 
    [[NSNotificationCenter defaultCenter] removeObserver:self name:ImageAnimatorDidStartNotification object:animatorViewController]; 
    [[NSNotificationCenter defaultCenter] removeObserver:self name:ImageAnimatorDidStopNotification object:animatorViewController]; 
    [animatorViewController stopAnimating]; 
    [animatorViewController.view removeFromSuperview]; 
    self.animatorViewController = nil; 
} 

- (void) clearAnimation { 
    [animatorViewController.view removeFromSuperview]; self.animatorViewController = nil; 
}