This is the JMCamController.h file
==================================
//
//  JMCamController.h
//  JMCamController
//
//  Created by Gary Gardner on 11/28/12.
//  Copyright (c) 2012 Gary Gardner. All rights reserved.
//
#import <Cocoa/Cocoa.h>
#import <AVFoundation/AVFoundation.h>
#import <QuartzCore/QuartzCore.h>
#import <CoreMedia/CoreMedia.h>
#import <AppKit/AppKit.h>

@class AVCaptureVideoPreviewLayer;
@class AVCaptureSession;
@class AVCaptureDeviceInput;
@class AVCaptureConnection;
@class AVCaptureDevice;

@interface JMCamController : NSObject
{
@private
	AVCaptureSession			*session;
	AVCaptureDeviceInput		*videoDeviceInput;
    AVCaptureVideoDataOutput    *videoDataOutput;

    //AVAssetWriter *assetWriter;
	AVAssetWriterInput *videoInput;

	NSArray						*videoDevices;
	NSArray						*observers;

    NSData                      *videoData;

	//CMTime frameDuration;
}

#pragma mark Device Selection
@property (retain) NSArray *videoDevices;
@property (assign) AVCaptureDevice *selectedVideoDevice;
//@property (retain) NSArray *observers;
//@property (retain) AVCaptureDeviceInput *videoDeviceInput;

#pragma mark Recording
@property (retain) AVCaptureSession *session;

#pragma mark Transport Controls
@property (readonly,getter=isPlaying) BOOL playing;

//@property (nonatomic) float framesPerSecond;

- (BOOL)setVideoDevice:(NSUInteger *)deviceNumber;
- (BOOL)run;
- (NSData *)getData;
- (void)refreshDevices;
- (void)videoBytes:(NSImage*)videoImage;
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection;
- (NSImage*)videoImageFromSampleBuffer:(CMSampleBufferRef*)sampleBuffer;
- (NSArray *)getDeviceArray;

@end


This is the JMCamController.m file
==================================
//
//  JMCamController.m
//  JMCamController
//
//  Created by Gary Gardner on 11/28/12.
//  Copyright (c) 2012 Gary Gardner. All rights reserved.
//

#import "JMCamController.h"

#define DEFAULT_FRAMES_PER_SECOND	5.0

@interface JMCamController ()  <AVCaptureVideoDataOutputSampleBufferDelegate>

// Properties for internal use
@property (retain) AVCaptureDeviceInput *videoDeviceInput;
@property (retain) NSArray *observers;

// Methods for internal use
- (void)refreshDevices;

@end

@implementation JMCamController

@synthesize videoDeviceInput;
@synthesize videoDevices;
@synthesize session;
@synthesize observers;

- (id)init
{
	self = [super init];
    //frameDuration = CMTimeMakeWithSeconds(1. / DEFAULT_FRAMES_PER_SECOND, 90000);

	if (self) {
		// Create a capture session
		session = [[AVCaptureSession alloc] init];

		// Capture Notification Observers
		NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
		id runtimeErrorObserver = [notificationCenter addObserverForName:AVCaptureSessionRuntimeErrorNotification
																  object:session
																   queue:[NSOperationQueue mainQueue]
															  usingBlock:^(NSNotification *note) {
                                                                  NSLog(@"an AVCaptureSessionRuntimeErrorNotification occurred %@", AVCaptureSessionErrorKey);
															  }];
		id didStartRunningObserver = [notificationCenter addObserverForName:AVCaptureSessionDidStartRunningNotification
																	 object:session
																	  queue:[NSOperationQueue mainQueue]
																 usingBlock:^(NSNotification *note) {
																	 NSLog(@"did start running");
																 }];
		id didStopRunningObserver = [notificationCenter addObserverForName:AVCaptureSessionDidStopRunningNotification
																	object:session
																	 queue:[NSOperationQueue mainQueue]
																usingBlock:^(NSNotification *note) {
																	NSLog(@"did stop running");
																}];
		id deviceWasConnectedObserver = [notificationCenter addObserverForName:AVCaptureDeviceWasConnectedNotification
																		object:nil
																		 queue:[NSOperationQueue mainQueue]
																	usingBlock:^(NSNotification *note) {
																		[self refreshDevices];
																	}];
		id deviceWasDisconnectedObserver = [notificationCenter addObserverForName:AVCaptureDeviceWasDisconnectedNotification
																		   object:nil
																			queue:[NSOperationQueue mainQueue]
																	   usingBlock:^(NSNotification *note) {
																		   [self refreshDevices];
																	   }];
        id invalidArgumentExceptionObserver = [notificationCenter addObserverForName:
                                               NSInvalidArgumentException
                                                                              object:nil
                                                                               queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *note) {NSLog(@"NSInvalidArgumentException Error");
                                                                               }];
		observers = [[NSArray alloc] initWithObjects:runtimeErrorObserver, didStartRunningObserver, didStopRunningObserver, deviceWasConnectedObserver, deviceWasDisconnectedObserver, invalidArgumentExceptionObserver, nil];

		// Select devices if any exist
		AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
		if (videoDevice) {
			[self setSelectedVideoDevice:videoDevice];
		} else {
			[self setSelectedVideoDevice:[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeMuxed]];
		}

		// Initial refresh of device list
		[self refreshDevices];
	}
	return self;
}

- (void)dealloc
{
	[videoDevices release];
	[session release];
	[videoDeviceInput release];
    [videoDataOutput release];

	[super dealloc];
}

- (void)didPresentErrorWithRecovery:(BOOL)didRecover contextInfo:(void  *)contextInfo
{
	// Do nothing
    NSLog(@"An error occurred and should be bubbled up");
}

- (void)refreshDevices
{
	[self setVideoDevices:[[AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] arrayByAddingObjectsFromArray:[AVCaptureDevice devicesWithMediaType:AVMediaTypeMuxed]]];

	[[self session] beginConfiguration];

	if (![[self videoDevices] containsObject:[self selectedVideoDevice]])
		[self setSelectedVideoDevice:nil];

	[[self session] commitConfiguration];
}

- (AVCaptureDevice *)selectedVideoDevice
{
	return [videoDeviceInput device];
}

- (void)setSelectedVideoDevice:(AVCaptureDevice *)selectedVideoDevice
{
	[[self session] beginConfiguration];

	if ([self videoDeviceInput]) {
		// Remove the old device input from the session
		[session removeInput:[self videoDeviceInput]];
		[self setVideoDeviceInput:nil];
	}

	if (selectedVideoDevice) {
		NSError *error = nil;

		// Create a device input for the device and add it to the session
		AVCaptureDeviceInput *newVideoDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:selectedVideoDevice error:&error];
		if (error) {
			//NSLog(@"deviceInputWithDevice: failed (%@)", error);
        }
		if (newVideoDeviceInput == nil || error) {
            //NSLog(@"deviceInputWithDevice: failed (%@)", error);
			/*dispatch_async(dispatch_get_main_queue(), ^(void) {
				[self presentError:error];
			});*/
		} else {
			if (![selectedVideoDevice supportsAVCaptureSessionPreset:[session sessionPreset]])
				[[self session] setSessionPreset:AVCaptureSessionPresetHigh];

			[[self session] addInput:newVideoDeviceInput];
			[self setVideoDeviceInput:newVideoDeviceInput];


            videoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
            [session addOutput:videoDataOutput];

            // Configure your output.
            dispatch_queue_t queue = dispatch_queue_create("myQueue", NULL);
            [videoDataOutput setSampleBufferDelegate:self queue:queue];
            //[videoDataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];

            NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey;
            NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA];
            NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:value forKey:key];

            [videoDataOutput setVideoSettings:videoSettings];

            dispatch_release(queue);

		}

	}

	[[self session] commitConfiguration];
}

- (BOOL)setVideoDevice:(NSUInteger *)deviceNumber
{
    BOOL success = NO;
    [self setSelectedVideoDevice:[videoDevices objectAtIndex:*deviceNumber]];

    AVCaptureDevice *aDevice = [self selectedVideoDevice];
    if (aDevice == nil) {
        success = NO;
    } else {
        success = YES;
    }
    return success;
}

- (BOOL)run
{
    // This method actually starts the cam running
    //NSLog(@"Inside the run method");
    [session startRunning];
    return YES;
}

- (NSData *)getData
{
    //NSLog(@"*** Inside getData()..... The bytes to be returned is: %lu", [videoData length]);
    return videoData;
}

// Delegate routine that is called when a sample buffer was written
- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection
{

    //NSLog(@"About to call imageFromSampleBuffer");
    //CIImage *image = imageFromSampleBuffer(sampleBuffer);

    //NSLog(@"About to call videoImageFromSampleBuffer");
    NSImage *image = [self videoImageFromSampleBuffer:&sampleBuffer];

    if (image == nil) {
        // Don't process the image
        //NSLog(@"The image would be nil, so nothing to do");
    } else {
        // process the image
        //NSLog(@"The image will be processed here");

        [self videoBytes:image];
        //[self convertVideoBytes:image];
    }

}

- (void)videoBytes:(NSImage*)videoImage
{
    //NSLog(@"Inside videoBytes");
    videoData = [videoImage TIFFRepresentation];

    // Print the bytes if you want.  Just uncomment this line
    //NSLog(@"Bytes:%lu", videoData.length);

}

- (NSImage*)videoImageFromSampleBuffer:(CMSampleBufferRef*)sampleBuffer
{

    //NSLog(@"Inside videoImageFromSampleBuffer method");

    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.
    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.
    static CGColorSpaceRef colorSpace = NULL;
    if (colorSpace == NULL) {
        colorSpace = CGColorSpaceCreateDeviceRGB();
        if (colorSpace == NULL) {
            // Handle the error appropriately.
            return nil;
        }
    }

    // Get the base address of the pixel buffer.
    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
    // Get the data size for contiguous planes of the pixel buffer.
    size_t bufferSize = CVPixelBufferGetDataSize(imageBuffer);

    // Create a Quartz direct-access data provider that uses data we supply.
    CGDataProviderRef dataProvider =
    CGDataProviderCreateWithData(NULL, baseAddress, bufferSize, NULL);
    // Create a bitmap image from data supplied by the data provider.
    CGImageRef cgImage =
    CGImageCreate(width, height, 8, 32, bytesPerRow,
                  colorSpace, kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little,
                  dataProvider, NULL, true, kCGRenderingIntentDefault);
    CGDataProviderRelease(dataProvider);

    // Create and return an image object to represent the Quartz image.
    //NSImage *image = [NSImage imageWithCGImage:cgImage];
    NSImage *image = [[NSImage alloc] initWithCGImage:cgImage size:NSZeroSize];
    CGImageRelease(cgImage);

    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);

    return image;
}

- (NSArray *)getDeviceArray
{
    NSUInteger arraySize = [videoDevices count];
    //NSLog(@"The number of items in the array is %lu", arraySize);
    NSMutableArray *mutableArray = [NSMutableArray array];

    int i = 0;
    for (i=0; i<arraySize; i++)
    {
        AVCaptureDevice *deviceString = [videoDevices objectAtIndex:i];
        //NSLog(@"The device = %@", deviceString);
        [mutableArray addObject:[deviceString description]];
    }
    NSArray *stringArray = [NSArray arrayWithArray:mutableArray];
    return stringArray;
}
@end