Thursday

DVD About

computer & technologyDVD stands for "Digital Video Disc" or Digital Versatile Disc", it is by far the most popular optical disc storage media format today. It's immediate predecessor was the VCD (or the "Video CD"). The VCD was a decent format for video data until video/movie producers created more technology into their film. The usual size of VCDs were 600-700 mega bytes, video quality was compared to the VCD's predecessor... the VHS tapes. VCD was a a great technology before as analog tapes deteriorate in due time. This equates to video and audio being technically lousy. VCDs offered more protection from the usual environment hazards of fluctuating temperature and humidity.

While VCDs were OK for the time-being, content producers (audio and video) became a little too impatient with how VCDs treated their masterpiece. Picture pixelation and unacceptable sound artifacts abound. Because 600-700 mega bytes limited the number of pixels and decibels a movie can burn in, people wanted better. And so, the DVD.

DVDs can store from 1.36 giga bytes to 15.9 giga bytes. That's a lot of data property to occupy. The basic types of DVD are referred to by a rough approximation of their capacity in gigabytes. A small DVD is called a "cookie" (well, because it is the same size as a cookie).

Here are more technical data about why DVDs store more than VCDs and CDs.

"DVD uses 650nm wavelength laser diode light as opposed to 780 nm for CD or 405 nm for HD-DVD or Blu-ray Disc. This permits a smaller pit to be etched on the media surface (1.32 µm for DVD versus 1.6 µm for CD) compared to CDs."

Imagine a glass jar... fill it up with pebbles and you'd probably have a jar of 100 pebbles, fill it up with sand and you'd probably have 5 billion sand grains in there. DVDs are like that, they allow laser to write data so tiny that it can accommodate more data in.

Of course, content producers loved it! Aside from picture and sound quality being perfect, they were able to squeeze into the DVD other content associated data (CAD). Those being director cuts, bloopers, cut scenes, directors commentaries, subtitling, audio language versions... some even put in games and more!

Dual layer recording: Another great feature of the DVD.

A Dual Layer disc differs from its usual DVD counterpart by employing a second physical layer within the disc itself. The drive with Dual Layer capability accesses the second layer by shining the laser through the first semitransparent layer.

Again, this equates to more data property for content producers. All these in the end do justice to the work of film and audio production AND brings consumers the best entertainment possible.

The DVD is a milestone product. I am very sure that from it will springboard more groundbreaking discoveries. For the meantime content producers are well satisfied with what the DVD offers. What is there left for the extra great space available is for ones imagination to conquer.


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