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DivX

According its pseudonymous authors the DivX codec – no relation to Circuit City’s now defunct DIVX digital video disk player – is based on Microsoft’s MPEG-4 video technology, with the addition of an MP3 audio stream. Since a DivX-compressed movie is between 10% and 20% the size of the original DVD – a typical 5GB, 80-90 minute DVD movie occupies about 650MB at a resolution of 640×480 – feature-length Hollywood movies can generally be stored on a single CD-ROM. Viewing is simply a matter of installing a widely available add-on to Microsoft’s Windows Media Player.

By mid-2000, students with access to fast online connections and other Internet-savvy consumers were beginning to use the new video format to trade high-quality film trailers and even full-length movies copied directly from DVDs. Fan sites that explained the technology and included links to new DivX-format releases available via the Internet soon appeared, just as MP3 sites had in the early days of online digital music. Many web sites provide recipes for copying a DVD to the DivX format, including various techniques for shrinking the film’s file size – such as by reducing the FPS rate from 30 to 24. Whilst its often possible to detect some pixelisation in complex moving images, and matching the sound track to the video can be a challenge for amateur editors, overall the quality is impressive and more than good enough for the average consumer.

At present DivX is a long way from reaching MP3’s mainstream distribution, and as a hacker’s creation, it might never break out of the underground communities. Notwithstanding the advances in compression technology, many believe that movies are unlikely to reach the status of online music anytime soon and that having to spend hours to download a film – for what is ultimately less than DVD quality – will deter most people from using the technology to any serious extent. Also, the fact that the process can take as much as 18 hours is likely to put off most people thinking of ripping a DVD to DivX format themselves. How things will develop on the legal front is unclear and it remains to be see what attitude the Motion Picture Association of America (MPAA) – which has already has launched lawsuits against individuals who provide technology for copying DVDs – and Microsoft adopt towards DivX.

By late 2001 an entirely new development of DivX was well advanced. The new DivX – being developed as an open-source project known as Project Mayo – is commonly referred to as “OpenDivX” or “DivX for Windows/Linux/Mac …..”. It is also differentiated from the original codec by its 4.xx (as opposed to 3.xx) version numbering scheme. Unlike the original DivX, OpenDivX has nothing whatsoever to do with Microsoft. However, it is technically similar to its predecessor, being also based on the MPEG-4 compression format. Its developers claim that it matches the high quality of the original codec whilst improving on its the compression ratio (meaning smaller file sizes).

 

Filed Under: Digital Video

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