Digital Audio Watermarks To Identify Movie Pirates

Digital Audio watermarks will now be used to identify which theater the pirate was sitting in, with a camcorder in his/her hand.

The audio watermark is created by slightly varying the waveform of music and speech at regular intervals.  In fact, this system is so good that they can not only identify the theatre where it was illegaly filmed but also which seat the pirate was sitting in.

From IEEE:  “The system is based on spread-spectrum audio watermarking for the multichannel movie soundtrack. It utilizes a stochastic model of the detection strength, which is calculated in the watermark detection process. Our experimental results show that the system estimates recording positions in an actual theater with a mean estimation error of 0.44 m. The results of our MUSHRA subjective listening tests show the method does not significantly spoil the subjective acoustic quality of the soundtrack. These results indicate that the proposed system is applicable for practical uses.”

See? its that simple.