An incomplete example.

AVCaptureDevice + AVCaptureSession Example

 
    AVCaptureSession *session = [[AVCaptureSession alloc] init];
    AVCaptureDevice *captureDevice = [[AVCaptureDevice alloc] init];
    
    // Add input/output devices
    // Check what media type is supported by the device
    NSArray *devices = [AVCaptureDevice devices];
    for (AVCaptureDevice *device in devices) {
        NSLog(@"Device name: %@", [device localizedName]);
        
        if ([device hasMediaType:AVMediaTypeVideo]) {
            if ([device position] == AVCaptureDevicePositionFront){
                NSLog(@"Device position: front");
                captureDevice = device;
                
                // We have a front-facing video device
                if (captureDevice != NULL) {
                    NSLog(@"Capture device found");
                    
                    // Add a device to the AVCaptureSession, AVCaptureDeviceInput
                    NSError *error;
                    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
                    if (!input) {
                        // Handle error
                    }
                    
                }

            } else {
                NSLog(@"Device position: back - Don't want");
            }
            
        }
    }
    
    
    // Start data flow - eventually want to also stopRunning
    [session startRunning];

Thanks