docs: public void setProcessing( VideoProcessing processing ) {
  		if( this.processing != null ) {
  			// kill the old process
  			this.processing.stopProcessing();
  		}
  
  		if (Looper.getMainLooper().getThread() != Thread.currentThread()) {
  			throw new RuntimeException("Not called from a GUI thread. Bad stuff could happen");
  		}
  
  		this.processing = processing;
  		// if the camera is null then it will be initialized when the camera is initialized
  		if( processing != null && mCamera != null ) {
  			processing.init(mDraw,mCamera,mCameraInfo,previewRotation);
  		}
  	}