AVCaptureSession Abandoned memory - allocations - instruments

I use default AVCaptureSession to capture the camera view.

Everything is working ok, i don't have any leaks, but when I use Allocations to find Abandoned memory after launching and closing AVCaptureDevice it shows me aproximately 230 objects, that are still live.

Here is my code:

Controller.h:

@interface Controller : UIViewController <AVCaptureVideoDataOutputSampleBufferDelegate> {
AVCaptureSession *captureSession;
AVCaptureDevice *device;

IBOutlet UIView *previewLayer;
}
@property (nonatomic, retain) AVCaptureSession *captureSession;
@property (nonatomic, retain) UIView *previewLayer;

- (void)setupCaptureSession;
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer 
       fromConnection:(AVCaptureConnection *)connection;
- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer;

Controller.m:

- (void)setupCaptureSession {       
    NSError *error = nil;

    [self setCaptureSession: [[AVCaptureSession alloc] init]];

    self.captureSession.sessionPreset = AVCaptureSessionPresetMedium;

    device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    if ([device isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus] && [device lockForConfiguration:&error]) {
        [device setFocusMode:AVCaptureFocusModeContinuousAutoFocus];
        [device unlockForConfiguration];
    }

    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device 
                                                                        error:&error];
    if (!input) {
        // TODO: Obsługa błędu, gdy nie uda się utworzyć wejścia
    }
    [[self captureSession] addInput:input];

    AVCaptureVideoDataOutput *output = [[[AVCaptureVideoDataOutput alloc] init] autorelease];
    [[self captureSession] addOutput:output];

    dispatch_queue_t queue = dispatch_queue_create("myQueue", NULL);
    [output setSampleBufferDelegate:self queue:queue];
    dispatch_release(queue);

    output.videoSettings = 
    [NSDictionary dictionaryWithObject:
     [NSNumber numberWithInt:kCVPixelFormatType_32BGRA] 
                                forKey:(id)kCVPixelBufferPixelFormatTypeKey];


    output.minFrameDuration = CMTimeMake(1, 15);

    [[self captureSession] startRunning];

    AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
    captureVideoPreviewLayer.frame = previewLayer.bounds;
    [previewLayer.layer insertSublayer:captur开发者_Go百科eVideoPreviewLayer atIndex:0];
    [previewLayer setHidden:NO];
}

// Delegate routine that is called when a sample buffer was written
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer 
       fromConnection:(AVCaptureConnection *)connection { 
    if (mutex && ![device isAdjustingFocus] && ![device isAdjustingExposure] && ![device isAdjustingWhiteBalance]) {
        // Create a UIImage from the sample buffer data
        mutex = NO;
        UIImage *image = [self imageFromSampleBuffer:sampleBuffer];

        image = [Tools rotateImage:image andRotateAngle:UIImageOrientationUp];  

        CGRect rect;
        rect.size.width = 210;
        rect.size.height = 50;
        rect.origin.x = 75;
        rect.origin.y = 175;

        UIImage *croppedImage = [image resizedImage:image.size interpolationQuality:kCGInterpolationHigh];
        croppedImage = [croppedImage croppedImage:rect];

        croppedImage = [self processImage:croppedImage];
        [NSThread detachNewThreadSelector:@selector(threadedReadAndProcessImage:) toTarget:self withObject:croppedImage];
    }
}

// Create a UIImage from sample buffer data
- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer {
    // Get a CMSampleBuffer's Core Video image buffer for the media data
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); 
    // Lock the base address of the pixel buffer
    CVPixelBufferLockBaseAddress(imageBuffer, 0); 

    // Get the number of bytes per row for the pixel buffer
    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer); 

    // Get the number of bytes per row for the pixel buffer
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer); 
    // Get the pixel buffer width and height
    size_t width = CVPixelBufferGetWidth(imageBuffer); 
    size_t height = CVPixelBufferGetHeight(imageBuffer); 

    // Create a device-dependent RGB color space
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 

    // Create a bitmap graphics context with the sample buffer data
    CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8, 
                                                 bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst); 
    // Create a Quartz image from the pixel data in the bitmap graphics context
    CGImageRef quartzImage = CGBitmapContextCreateImage(context); 
    // Unlock the pixel buffer
    CVPixelBufferUnlockBaseAddress(imageBuffer,0);

    CGContextRelease(context); 
    CGColorSpaceRelease(colorSpace);

    UIImage *image = [UIImage imageWithCGImage:quartzImage];

    CGImageRelease(quartzImage);

    return (image);
}

And i clean everything with this code:

- (void)cancelTapped {
    [[self captureSession] stopRunning], self.captureSession = nil; 

    for (UIView *view in self.previewLayer.subviews) {
        [view removeFromSuperview];
    }

    [self dismissModalViewControllerAnimated:YES];
}

- (void)dealloc {
    [super dealloc];

    [captureSession release];
    [device release];
    [previewLayer release];
}

And instruments show me something like this: http://i.stack.imgur.com/NBWgZ.png

http://i.stack.imgur.com/1GB6C.png

Any ideas what I am doing wrong?

---

- (void)setupCaptureSession {       
   NSError *error = nil;

   [self setCaptureSession: [[AVCaptureSession alloc] init]];
   ...

That leaks the capture-session, which will keep all inputs and outputs and all their little internal helpers alive.

Two options:

AVCaptureSession *session = [[AVCaptureSession alloc] init];
self.captureSession = session;
[session release], session = nil;
// or:
self.captureSession = [[[AVCaptureSession alloc] init] autorelease];

---

- (void)dealloc {
    [super dealloc];

    [captureSession release];
    [device release];
    [previewLayer release];
}

super dealloc should be called after the other releases, or the memory of your instance may not contain valid pointers to these objects that you are releasing and thus you will not release them, especially if they are nil.