Downloading MP3s from the Net—whether it be music-swapping through Napster or just visiting sites to search for the music you want—has today become second nature to most computer users. The prime reason behind this popularity is the fact that MP3s are small files, easy to download and store on your hard disk or burn on a CD, and give near CD-quality music. Now, the video front also seems to be poised for the same scenario.

Distributing good-quality digital video over the Net has been a very cumbersome task, because videos are huge files that take a long time to download and are difficult to store on your hard disk. Moreover, the quality of the downloaded file makes the whole process a task that’s better left undone. However, the spread of broadband (which translates to much higher bandwidths) coupled with two ‘hacker’ utilities, DeCSS and DivX, have opened the doors to online distribution of good-quality digital video. In the process, the two utilities have also opened a Pandora’s box of issues and controversies, not to mention lawsuits.

DeCSS is a small utility that breaks the encryption scheme of DVDs and allows you to copy the contents onto your hard disk so that you can view it on your PC. DeCSS was initially developed to allow Linux users to watch DVDs on their PCs, because there were no DVD players for the Linux operating system. It has, however, now become the subject of lawsuits backed by the Motion Picture Association of America (MPAA) and the DVD Copyright Control Association (DVD CCA), on charges of promoting piracy, circumventing copy protection, etc. (See ‘The Battle Over DeCSS’, page 128, PC Quest February 2001 for more on how DeCSS works and the legal issues involved.)

Unencrypted DVD content got through DeCSS is, however, difficult to share online because of its huge size, which is between 4–9 GB. This is where DivX—usually written as DivX;-)—plays a crucial role. The smiley face is intended to satirize a now defunct technology by the same name that was intended to prevent piracy.

DivX allows a 90-minute DVD movie to be compressed to about one-tenth or less of its original size, thereby making it small enough to download from the Net and even burn on a regular 650 MB CD, without much loss in quality. With DivX, it’s possible to download a two-hour movie in 45 minutes to two hours, depending on your Net connect.

The codec (compression-decompression) was developed by a French video engineer and hacker, Jerome Rota, and has gained immense popularity in the hacker world since its release last year. DivX uses MPEG-4 for video encoding (hacked from a beta version of Windows Media Player) and is available for all operating systems. You can download and play DivX encoded movies using Windows Media Player.

How DivX works

Encoding a DVD movie is a long process that can take up to 10 hours and requires lots of hard-disk space and processing power. You need a variety of software including DivX for the task. The process begins with using DeCSS or an application like SmartRipper to rip the files off the DVD and copy them to your hard disk. These files have a VOB extension and can occupy up to 9 GB of hard disk space. Then, you use an application like FlasK MPEG that uses the DivX codec to encode the movie into a DivX data stream. To handle the audio encoding, you need a codec like Radium MP3, an application to extract the audio from the VOB file, another one to enhance its quality, and finally an encoder to encode the file into MP3 or other audio formats. Then, you need to merge the audio with the video. Software like VirtualDub lets you encode audio and merge the audio and video simultaneously. It also gives you the option of encoding audio into MP3 or DivX audio. To play the encoded file, you need the DivX codec to decode the movie (this happens automatically), and Windows Media Player.