Jari Ketola
3 Nov 2005 1:35
A new technology for watermarking movies has been unveiled at a conference held by the DVD Forum in Paris. The new technology relies on unnoticeable watermarks on the audio track instead of more commonplace image based watermarks. Future movies will include the watermarking on the audio track, and HD-DVD players will look for these marks on discs played on the device.
The watermarking works by encoding a digital signal to the audio track by varying its waveform. Even though unnoticeable to the human ear, the player can easily Decode the signal and detect if the copy has been made in a movie theatre.
Similar watermarking will be implemented on consumer discs as well. When such a watermark is detected, the player will check if the disc played is genuine or not, and if it's not, the player will shut itself down.
In order for the player to determine the copy illegal the watermark signal must be present for an extended period of time. That should prevent the "false positives" that could be caused by, for example, taking a home video in an environment with a watermarked movie playing in the background.
Electronic Frontier Foundation's intellectual property attorney Fred von Lohmann is somewhat concerned about implementing a new watermarking technology. "For any watermarking scheme to be effective, technology companies have to be forced to re-engineer playback devices to detect the watermarks," von Lohmann told New Scientist. "The risk is that Hollywood starts dictating the redesign of existing DVD drives, CD drives, hard drives, and personal computers, all to buttress the watermark."
Watermarking can be very effective indeed in preventing pirated copies from being viewed on next generation players. With HDCP being mandatory on all "HD Ready" devices, the entertainment industry is pretty much making sure that no HD player with the watermark check bypassed will be able to enter the market.
Source:
New Scientist