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What is DVD and How Does it Work?

What is DVD and How it Works

DVD stands for Digital Versatile Disc. It is also known as Digital Video Disc.

The DVD format saw standardisation in 1995. Electronics giants Philips, Sony, Panasonic and Toshiba formed a consortium for that purpose.

Edge Over VHS

The main idea was to provide a higher-quality alternative to the VHS.

It offered features such as different widescreen aspect ratios, chapter markers and custom menu.

DVD soon emerged as a reliable optical media for the storage of digital content. This included not only video but computer software and any files that can be created with a computer or read by it.

The standout advantage is no video quality loss even after repeated viewings as is the case with VHS with frequent tape rewinding.

Difference Between a CD and DVD

Physically, you can’t tell the difference between a CD and a DVD. They’re of the same size.

Where they differ is in the storage capacity – the size of the digital content they can store.

A standard DVD can store at least seven times more content than a CD.

Also, CD’s data transfer rate ranges from 1.4 to 1.8 MB/s. DVD’s data transfer rate sits at an average of 11Mb/s.

How a DVD Works

DVD uses patterns of dots to store data. A laser is used to burn these dots to the DVD.

Dots are differentiated in terms of spacing and brightness and darkness. These will be read accordingly by a computer DVD drive or a DVD player.

MPEG-2 and DVD

Video in a DVD is compressed in the MPEG-2 format with a resolution of 480p. This allows for a reasonable storage space of 30MB per minute of video.

That said, a two hour novie would take up around 3.6GB of disc space.

Common Types of DVD : DVD-5 and DVD-9

The common types of DVD are DVD-5 and DVD-9.

DVD-5 is called so because it allows for about 5GB of storage space.

DVD-9 offers nearly double the storage space of DVD-5 at 8.5GB of storage space. DVD-9 is actually two DVDs in one. It is one DVD-5 placed on top of another DVD-5 on a single disc. Of course, you won’t see the two discs sticking together. They are two layers of the disc not visible to the naked eye.

Note that DVD-9 isn’t available in DVD+/-RW, only as DVD+/-R.

If you want to burn a movie that is longer than 2 hours you should opt for for a DL (Dual Layer) 8.5GB disc.

Be sure top have a DVD writers which supports dual layer disc burning.

Dual- Sided DVD

A dual-sided DVD can hold about 9.4 GB of data. That’s twice the size of a DVD-5 (4.7GB x 2).

A dual-layer, dual-sided DVD boasts a storage space of 17.1GB of data.

The Future of DVD

DVD used to be the go-to medium for the storege of high-quality video in the late 1990s and early 2000s.

These days with video streaming and video file playback through USB-based storage devices like flash drives and external hard disks, have pushed down DVD off the popularity charts. Still, there’s much interest in DVDs in certain quarters.

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