Goodbye to the Video Store

Streaming video: For too long, “video-on-demand” has promised more than it could deliver.
But new ways are emerging for shrink-wrapping massive video files for delivery over the Internet

It sounds like the movie addict's ultimate fantasy: a TV-mounted set-top box that taps the film libraries of Hollywood's big studios. A film buff could peruse thousands of titles spanning dozens of genres, from enduring classics to the latest blockbuster releases. After deciding what to watch, viewers would enter a password, confirm credit-card details, then sit back as 5.1-channel surround-sound video streams from a remote web server into a home-theatre system in their living room.

Too good to be true? For the moment, yes. Bespoke video-on-demand is at least three years away. But the difference now is that Movielink—a recently formed joint venture between MGM, Paramount, Sony, Universal and Warner Bros—is preparing a collective library for just such a service. The venture intends to serve up an almost unlimited selection of films over the Internet‹and, eventually, through a web- connected set-top box.

There is only one problem: the current scheme for converting an average two-hour epic into a digital file results in about five gigabytes of data—equivalent to five billion letters of the alphabet (ie, close to a billion words in English). With each byte comprising eight binary digits (or “bits”), a typical movie contains no less than 40 billion bits of data. Trying to stuff that many zeros and ones through the copper lines that link most homes to the Internet—even via a broadband DSL (digital subscriber line) or cable modem connection—would take all day. If there is ever going to be a profitable online video service, content creators in Hollywood and elsewhere must figure out how to squeeze those hefty film files through narrow digital pipelines.

That is where “codecs” (compression/decompression algorithms) come in. These are sophisticated, and often proprietary, mathematical formulae that can quickly scrunch hours of digital video and determine where best to make nips and tucks unnoticeable to a viewer. The end result is a compact digital file.

One of the most prevalent codecs is MPEG-2. Established by the Moving Picture Experts Group in 1994 as a standard for digital television, MPEG-2 governs DVDs, satellite TV and digital cable content. This requires a minimum transmission rate of two megabits per second for video scenes with little movement in them and up to 80 megabits per second for action scenes, so there is little hope of sending MPEG-2 video to homes using even the fastest of Internet connections available today—which, at best, barely break the one megabit per second barrier.