show.rb

before_filter :fetch_proper_params, :only => [:show]

def show 
  render
end

private

  def fetch_proper_params
    @course = Course.find(params[:course_id])
    @video = permitted_to?(:browse, :videos) ? @course.videos.find(:first) : Video.find(params[:id])
    add_crumb "Watching #{@video.title}", permitted_to?(:browse, :videos) ? video_path(@video) : course_video_path(@course, @video)
  end