Macruby live(ish) moustachification in Mac OS X Lion.

gistfile1.rb

framework 'Cocoa'
framework 'avfoundation'

class FaceDetectionDelegate
  attr_accessor :window
  
  def applicationDidFinishLaunching(aNotification)
    width = 640
    height = 480
    
    session = AVCaptureSession.alloc.init
    session.sessionPreset = AVCaptureSessionPreset640x480
    
    @cg_context = CGBitmapContextCreate(nil, width, height, 8, 4*width, CGColorSpaceCreateDeviceRGB(), KCGImageAlphaNoneSkipFirst)
    
    @tache_array = []
    
    detectorOptions = {CIDetectorAccuracy: CIDetectorAccuracyLow}
    @detector = CIDetector.detectorOfType "CIDetectorTypeFace", context:nil, options:detectorOptions
    
    url = NSURL.URLWithString("http://dl.dropbox.com/u/349788/mustache.png")     
    source = CGImageSourceCreateWithURL url, nil
    @tache = CGImageSourceCreateImageAtIndex source, 0, nil
    
    window.delegate = self    
    
    device = AVCaptureDevice.defaultDeviceWithMediaType AVMediaTypeVideo    
    input = AVCaptureDeviceInput.deviceInputWithDevice device, error:nil
    output = AVCaptureVideoDataOutput.alloc.init
    output.alwaysDiscardsLateVideoFrames = true

    queue = Dispatch::Queue.new('cameraQueue')
    output.setSampleBufferDelegate self, queue:queue.dispatch_object
    output.setVideoSettings KCVPixelBufferPixelFormatTypeKey => KCVPixelFormatType_32BGRA, KCVPixelBufferWidthKey => width, KCVPixelBufferHeightKey => height
    
    session.addInput input
    session.addOutput output
    
    @preview_layer = AVCaptureVideoPreviewLayer.layerWithSession session
    @preview_layer.frame = [0.0, 0.0, width, height]
    @preview_layer.videoGravity = AVLayerVideoGravityResizeAspectFill
    mirror = CGAffineTransformMakeScale -1, 1
    @preview_layer.affineTransform = mirror
        
    session.startRunning

    window.setFrame [0.0, 0.0, width, height], display:true, animate:true
    window.center
    
    window.contentView.wantsLayer = true
    window.contentView.layer.addSublayer @preview_layer

    window.orderFrontRegardless
  end
  
  def add_tache_layer
    tache = CALayer.layer
    tache.contents = @tache
    tache.contentsGravity = KCAGravityResize
    @tache_array << tache
    @preview_layer.addSublayer tache
    tache
  end
  
  def captureOutput(captureOutput, didOutputSampleBuffer:sampleBuffer, fromConnection:connection)    
    imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)    
    image = CIImage.imageWithCVImageBuffer(imageBuffer)
        
    features = @detector.featuresInImage(image)

    Dispatch::Queue.main.sync do
      @tache_array[features.size..@tache_array.size].each {|t| t.opacity = 0} rescue nil # hide any unattached taches
      
      features.each.with_index do |feature, i| 
                
        if feature.hasRightEyePosition && feature.hasLeftEyePosition && feature.hasMouthPosition
          w = feature.bounds.size.width
          h = feature.bounds.size.height/5

          tache = @tache_array[i] || add_tache_layer
          tache.opacity = 0.9
          tache.bounds = [0, 0, w, h]
          tache.position = [feature.mouthPosition.x, feature.mouthPosition.y+10]
          rotation = Math.atan2(feature.rightEyePosition.y-feature.leftEyePosition.y,feature.rightEyePosition.x-feature.leftEyePosition.x)
          tache.setValue rotation, forKeyPath: "transform.rotation"
        end
      end
    end
    nil
  end

  def windowWillClose(sender); exit(1); end

end

# Create the Application
application = NSApplication.sharedApplication
NSApplication.sharedApplication.activationPolicy = NSApplicationActivationPolicyRegular
application.delegate = FaceDetectionDelegate.alloc.init
# create the Application Window
frame = [0.0, 0.0, 330, 250]
window = NSWindow.alloc.initWithContentRect frame, 
                                  styleMask: NSTitledWindowMask | NSClosableWindowMask,
                                    backing: NSBackingStoreBuffered,
                                      defer: false

application.delegate.window = window
window.orderOut(nil)
window.display
puts "Starting the app..."
application.run