Scott Smitelli here, the author or âFun with YouTubeâs Audio Content ID System.â There are a few interesting points worth mentioning about YouTubeâs implementation. Granted, some of these things may have changed (the original research is a year and a half old at this point) but these facts held true at one point.
First, I discovered that by disputing a copyright claim, your video immediately becomes unblocked/unmuted/un-whateverâd until the owner of the material weighs in. In my case, I uploaded a full, unmodified copy of Stairway to Heaven, which was naturally blocked as matching content from WMG, I believe. I disputed the claim over a year ago, and to this day it is still awaiting a response from the rights holder. My guess is that some of these larger media behemoths have a huge backlog of disputes that they never get through.
Secondly, the audio and video detectors seem to work independently. I learned firsthand from a YouTube employee that the audio matching is performed by a system created by Audible Magic, whereas the video matching was built in-house by Google. Itâs difficult to determine which system is actually doing the match for movies and TV shows.
Assuming your content is being matched by the video portion of the detector, it was at one point possible to thwart the system by flipping the video horizontally â such that text is mirror-imaged and people seem to drive their cars on the wrong side of the road. The YouTube employee I spoke with acknowledged that fact, and said that the rights holders had expressed concern about the loophole. Ultimately, the rationale was that it took too much effort for most users to modify videos in that way, and that ânobody wanted to watch a video that had been flipped,â so the weakness stayed. You could also invert all the colors to get past the system. It looked pretty godawful, but a quick Control+Command+Option+8 on a Mac would invert the screen and make the video colors normal, albeit slightly darker than you would expect.
Whether those tricks still work today, Iâm not sure. But that is the way it once was. Itâs tough to do any real substantive research on YouTubeâs guts, because theyâre so opaque about announcing changes to the system (and understandably so).
Audible Magic has some patents that are viewable at http://audiblemagic.com/company/patents.asp â which give just enough insight into how the system works overall while simultaneously omitting most of the critical information you would need to really dig into it. For a more complete sense on how a competing system works, check out this paper explaining how Shazam works: http://www.ee.columbia.edu/~dpwe/papers/Wang03-shazam.pdf
Iâd love to share everything Iâve learned with anybody who was interested. Iâm parallax AT csh DOT rit DOT edu. Iâm no expert by any means, but I do have a passion for this kind of thing. I try not to have any overt opinions on the state of copyright in this country, and I have nothing against fingerprinting software in general. Itâs a tool which is neither good nor evil. Itâs all in how you choose to use it.