iOS7 - Outputting frames with AVCaptureMetadataOutput? - iphone

Question

I am trying to use the iOS7 QR reading functions in the AVFoundation framework using the following code:
-(void)setupCaptureSession_iOS7 {
self.session = [[AVCaptureSession alloc] init];
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device
error:&error];
if (!input)
{
NSLog(#"Error: %#", error);
return;
}
[session addInput:input];
//Turn on point autofocus for middle of view
[device lockForConfiguration:&error];
CGPoint point = CGPointMake(0.5,0.5);
[device setFocusPointOfInterest:point];
[device setFocusMode:AVCaptureFocusModeContinuousAutoFocus];
[device unlockForConfiguration];
//Add the metadata output device
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
[session addOutput:output];
NSLog(#"%lu",(unsigned long)output.availableMetadataObjectTypes.count);
for (NSString *s in output.availableMetadataObjectTypes)
NSLog(#"%#",s);
//You should check here to see if the session supports these types, if they aren't support you'll get an exception
output.metadataObjectTypes = #[AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeUPCECode];
output.rectOfInterest = CGRectMake(0, 0, 320, 480);
[session startRunning];
// Assign session to an ivar.
[self setSession:self.session];
}
This code obviously doesn't render the frames to the screen (yet). This is because, instead of using the AVCaptureVideoPreviewLayer class to display the preview, I need to display the frames as a UIImage (this is because I have want to display the frames multiple times on the view).
If I use AVCaptureVideoDataOutput as the output, I'm able to export the frames using by grabbing them from the captureOutput:didOutputSampleBuffer:fromConnection: callback. But I can't find an equivalent way to call get the frameBuffer when using AVCaptureMetadataOutput as the output.
Does anyone have any idea how to do this?