The movie industry has another weapon in its battle against piracy. From 2006 the soundtracks of all major movies released to the cinema will contain an audio 鈥渨atermark鈥�. The high-definition DVD players due to be launched next year by Toshiba will be able to detect it.
The watermark is introduced when the soundtrack is being mixed, by slightly varying the waveform of speech and music at regular intervals. The variations are too subtle to be audible, but the pattern can easily be detected by a decoder in the player.
The system was unveiled by Alan Bell of Warner Bros Entertainment at a conference held by the DVD Forum last week in Paris, France. The forum, which is an association of DVD-industry companies, is finalising the standards for the high-definition DVD system.
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Legal HD DVDs will not contain the watermark, so if the system detects the code, it will mean the film is a pirate version made by someone pointing a camcorder and microphone at a cinema screen, or copying a film print to video. When the code is detected, the DVD player will stop the movie.
Since HD DVD and Sony鈥檚 rival Blu-ray use very similar movie encryption systems, watermarking is also likely to be used with Blu-ray.
A variation of the system can prevent the playback of copy discs that have been made by illegally pointing a camcorder at a high-quality home screen while it is playing a legitimate disc. New movie discs will have a different, consumer audio watermark. If a player senses this it will check whether the disc was factory pressed, and if not, shut down.
