Getting to Know DVDs
The DVD is the centerpiece to a home theater. DVD offers an inexpensive, easy-to-use, high-quality system for movies and movie soundtracks. And the better your display (such as an HDTV), the more you’ll appreciate a high-quality signal being fed to your display.
Chances are good that you're already familiar with the DVD (after all, DVD has been one of the most — if not the most — rapidly adopted new technologies of all time). But DVD is a moving target — manufacturers of DVD players have continually improved their gear and added new features that both improve picture quality and make your DVD viewing more convenient.
Here are some DVD facts to consider:
The DVD is a 12cm optical disc (by the way, optical means that the data on the disc is read by a laser). From a distance, a DVD looks just like a CD. The big difference between the DVD and the CD is the format that each uses for burning those little digital pits into the disc (pits that turn into digital 1s and 0s when the laser reads them).
Because the DVD uses a more complex formatting scheme, it has the capacity to store a lot more data than a CD. A DVD can hold a minimum of 4.7GB of data (dual-layer DVDs can hold more), whereas a CD’s limit is about 700MB. So a DVD can hold more than six times as much data as a CD.
A DVD’s extra capacity is crucial to home theater because it lets the DVD store about two hours of high-quality digital video and digital audio signals using Dolby Digital or DTS and an analog two-channel stereo signal as well. A CD, well, it can’t hold more than a few dozen minutes of this kind of home theater data.
You’ll also hear about dual-layer and double-sided DVDs. These discs (which work just fine in any DVD player) hold even more data for long movies and cool extras, such as deleted scenes or director commentary. The additional space is made possible by putting the extra data on a different layer of the DVD or on the other side (so you just have to flip the disc).
The DVD stores its information in a digital format and, for video, uses the MPEG format. The DVD can also hold the audio soundtracks that correspond to this video in a variety of Dolby and DTS formats, as well as store cool extra features, such as additional foreign language soundtracks, subtitles, and scene indexes (which let you skip to different scenes in a movie, just like you can skip to different songs on a CD).
The DVD can also do something that most other home theater source devices can’t do. It can display true widescreen video.
Not all DVDs (the discs themselves, not the DVD player) give you a true widescreen anamorphic picture. Many DVDs have been formatted in the standard 4:3 aspect ratio instead. If you want widescreen, you need to choose DVDs with labels that say anamorphic, widescreen, 16:9, or something similar. Many movie companies put both versions on a single disc (using dual-layer technology) or release both widescreen and Pan and Scan DVD versions of an individual movie.