Imagine if there were a Shazam for movies

Ever channel-surfed and come across a film you know but just can't name? You recognize the actors, the scene, even bits of dialogue, but the name of the film escapes you? I've always wondered if there could be an app for that mystery. Something like Shazam, the smartphone app able to name a song simply by hearing a few bars of the track. It's a very powerful tool, and I've used it several times when my friends and I heard a song on the radio we couldn't identify. Now take that to movies. What if a Shazam-like app could be applied to films, whereby you open the app on your phone and hold it up to the TV screen. Either visually or via audio, the app can tell which film is being broadcast, thanks to its database of thousands of popular films and their scenes and dialogue. It would be very cool if the app could ID a movie with a photograph, but I wonder how difficult that would get. Maybe listening to dialogue would be simpler? (Although how would it identify The Artist?) I know this is wishful thinking, but perhaps a savvy entrepreneur will come across this blog and get working on this idea. I sure don't have the time or know-how to get this off the ground. As you all know, running DJ is a full-time job. Would you get this app if it were ever created?