The new technological weapon is content-recognition software, which makes it possible to identify copyrighted material, even, for example, from blurry video clips.
The technology could address what the entertainment industry sees as one of its biggest problems--songs and videos being posted on the Web without permission.
Last week, Vance Ikezoye, the chief executive of Audible Magic in Los Gatos, Calif., demonstrated the technology by downloading a two-minuteand feeding it into his company's new video-recognition system.
The clip--drained of color, with dialogue dubbed in Chinese--appeared to have been recorded with a camcorder in a dark movie theater before it was uploaded to the Web, so the image quality was poor.
Still, Ikezoye's filtering software quickly identified it as the sword-training scene that begins 49 minutes and 37 seconds into the Miramax film Kill Bill: Vol. 2.
The entertainment industry is clamoring for Internet companies to adopt the technology for music files as well as for video clips. The social networking site MySpace, owned by News Corp., said last week that it would use Audible Magic's system to identify copyrighted material on its pages. But not every Internet company is rushing to go along. The video-sharing site YouTube, which Google bought last year, is the major holdout so far.
Though YouTube's co-founders said publicly that they would startby the end of last year, the site has yet to do so. And they have further angered some media companies by saying they would only use such technology to detect clipsowned by companies that agree to broader licensing deals with YouTube.
The pressure is on. Executives at media companies like NBC and Viacom have criticized Google for the delay. Earlier this month,of its shows, like music videos from MTV and excerpts from Comedy Central's The Daily Show.
In a statement, YouTube said that identifying which video clips had been uploaded without permission was a complex problem that required the cooperation of the copyright owners. "On YouTube, identifying copyrighted material cannot be a single automated process," it said in the statement.
The systems being developed by companies like Audible Magic and Gracenote make use of vast databases that store digital representations of copyrighted songs, TV shows and movies.
When new files are uploaded to a Web site that is using the system, it checks the database for matches using a technique known as digital fingerprinting. Copyrighted material can then be blocked or posted, depending on whether it is licensed for use on the site.
"This is capable of helping the film and TV studios comprehensively protect their works," Ikezoye said. "This could put the genie back in the bottle."
Audio fingerprinting technologies have been used successfully for some time to detect copyrighted music on file-sharing networks and, to a smaller degree, to identify music tracks on social-networking Web sites like MySpace.
Systems that can identify video files hold even greater promise to improve relations between traditional media companies and Internet companies like YouTube. But the technology is not quite ready.
"Video is much more complex to analyze, and more information needs to be captured in the fingerprint," said Bill Rosenblatt, president of GiantSteps Media Technology Strategies, a consulting firm based in New York. He noted that there were also more ways to fool the technology--for example, by cropping the image.
Screening for video is also more difficult because of the sheer volume of new material broadcast on television each day, all of which must be captured in the database.
And deploying any type of fingerprinting technology can carry a price. Users tend to leave filtered Web sites and migrate to more anything-goes online destinations.