How to detect faces within a video session with iOS 5 - iphone

Question

Within my App I'm using a videosession where I can take pictures with. However I'd like to have face detection within this videosession. I looked at Apple's example "SquareCam" which is exactly what I'm looking for. However implementing their code in my project is driving me bonkers.
#import "CaptureSessionManager.h"
#import <ImageIO/ImageIO.h>
#implementation CaptureSessionManager
#synthesize captureSession;
#synthesize previewLayer;
#synthesize stillImageOutput;
#synthesize stillImage;
#pragma mark Capture Session Configuration
- (id)init {
if ((self = [super init])) {
[self setCaptureSession:[[AVCaptureSession alloc] init]];
}
return self;
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
NSLog(#"memorywarning");
// Release any cached data, images, etc that aren't in use.
}
- (void)addVideoPreviewLayer {
[self setPreviewLayer:[[[AVCaptureVideoPreviewLayer alloc] initWithSession:[self captureSession]] autorelease]];
[[self previewLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
}
- (void)addVideoInput {
AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([videoDevice isFocusModeSupported:AVCaptureFocusModeLocked]) {
NSError *error = nil;
if ([videoDevice lockForConfiguration:&error]) {
NSLog(#"focus");
videoDevice.focusMode = AVCaptureFocusModeLocked;
videoDevice.focusMode = AVCaptureFocusModeContinuousAutoFocus;
//videoDevice.focusMode = AVCaptureSessionPresetPhoto
videoDevice.whiteBalanceMode = AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance;
[captureSession setSessionPreset:AVCaptureSessionPresetPhoto];
[videoDevice unlockForConfiguration];
}
else {
}
}
// Respond to the failure as appropriate.
if (videoDevice) {
NSError *error;
AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if (!error) {
if ([[self captureSession] canAddInput:videoIn])
[[self captureSession] addInput:videoIn];
else
NSLog(#"Couldn't add video input");
}
else
NSLog(#"Couldn't create video input");
}
else
NSLog(#"Couldn't create video capture device");
}
- (void)addStillImageOutput
{
[self setStillImageOutput:[[[AVCaptureStillImageOutput alloc] init] autorelease]];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[[self stillImageOutput] setOutputSettings:outputSettings];
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
[[self captureSession] addOutput:[self stillImageOutput]];
[outputSettings release];
}
- (void)captureStillImage
{
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(#"about to request a capture from: %#", [self stillImageOutput]);
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments) {
NSLog(#"attachements: %#", exifAttachments);
} else {
NSLog(#"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[self setStillImage:image];
[image release];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:nil];
}];
}
- (void)dealloc {
[[self captureSession] stopRunning];
[previewLayer release], previewLayer = nil;
[captureSession release], captureSession = nil;
[stillImageOutput release], stillImageOutput = nil;
[stillImage release], stillImage = nil;
[super dealloc];
}
#end
Besides my videosession I did succeeded with recognizing faces within a UIImage which I imported inside my project. I did this with the example of #Abhinav Jha (How to properly instantiate CIDetector class object in iOS 5 face detection API).
CIImage *ciImage = [[CIImage alloc] initWithImage:[UIImage imageNamed:#"Photo.JPG"]];
if (ciImage == nil)
[imageView setImage:[UIImage imageNamed:#"Photo.JPG"]];
NSDictionary *options = [[NSDictionary alloc] initWithObjectsAndKeys:
#"CIDetectorAccuracy", #"CIDetectorAccuracyHigh",nil];
CIDetector *ciDetector = [CIDetector detectorOfType:CIDetectorTypeFace
context:nil
options:options];
NSArray *features = [ciDetector featuresInImage:ciImage];
NSLog(#"no of face detected: %d", [features count]);
Hope someone can point me in the right direction with combining the two examples!