Converting a regular Youtube ‘link’ into an embedded video

I do this quite often for clients, the gist of it is that you parse out the ID from the URL, then generate the iframe HTML using this.

def youtube_embed(youtube_url)
  if youtube_url[/youtu\.be\/([^\?]*)/]
    youtube_id = $1
  else
    # Regex from # http://stackoverflow.com/questions/3452546/javascript-regex-how-to-get-youtube-video-id-from-url/4811367#4811367
    youtube_url[/^.*((v\/)|(embed\/)|(watch\?))\??v?=?([^\&\?]*).*/]
    youtube_id = $5
  end

  %Q{<iframe title="YouTube video player" width="640" height="390" src="http://www.youtube.com/embed/#{ youtube_id }" frameborder="0" allowfullscreen></iframe>}
end

youtube_embed('youtu.be/jJrzIdDUfT4')
# => <iframe title="YouTube video player" width="640" height="390" src="http://www.youtube.com/embed/jJrzIdDUfT4" frameborder="0" allowfullscreen></iframe>

I put this in a helper. Change the height, width and options to taste.