Digital Versatile Disc is popularly known as DVD. It is a type of optical disc used for data storage and multimedia platforms. In this article we will discuss about what is DVD, its History, Storage Capacity, Structure, Types.
What is DVD (Digital Versatile Disc)
The Digital Versatile Disc was created as a replacement for VHS tapes, but it quickly gained popularity as a data storage device. The audio CD was created in 1972 as a form of entertainment. The multimedia compact disc (MMCD) and the super density (SD) disc are the two video disc formats developed in 1993. Later, it took over CD in 1997 as a data storage and entertainment medium. In 1996, the movie Twister was the first movie out on DVD.
Drives use lasers to read the data, which are in the form of binary code. This data is recorded on the disc in the form of small pits that trace a spiral track between the Disc’s Centre and its outer edge. However, the laser of Digital Versatile Disc emits red light at its shorter wavelengths as compared to the red light of the CD laser.
Release Date of Digital Versatile Disc
It was developed in 1995 by mainly four standard companies like Philips, Sony, Toshiba and Panasonic and late in 1996 it was released.
Storage Capacity
Presently the storage capacity is upto 17.08GB and can store any type of digital data. The main purpose of DVDs is to store software and other files as well as a player to watch video programs. As compared to compact disc, it offers higher storage capacity within the same dimensions.
Internal Structure
A DVD is capable of resolving shorter pits on narrow spaced tracks, thereby making space for storage density. Additionally, it comes with single sided and double sided versions that means one or two layers of data in one side of the disc. More than 16 gigabytes of data can be stored on a dual-layer DVD, which is more than 10 times the capacity of a CD-ROM.
A single sided DVD holds 4 gigabytes which is more than sufficient to store 2 hours of movies. Later, it became the primary media for watching movies at home almost immediately after the first Digital Versatile Disc players were produced, nearly totally replacing videotape.
光盘的方便,以及改进的曲ality of the video images, the interactivity of the digital controls, and the inclusion of several new features packed inside the discs’ capacious storage, were immediately appreciated by consumers.
类型的dvd
The types of DVDs may be classified based on
- Its applications
- Its Capacity
- Its Physical Size
类型的dvdbased Upon its Applications
The various types of DVDs based upon its applications are:
DVD ROM
Only used for the purpose of reading and not available for writing.
DVD-R
We can record any type of audio. Whereas R stands for recordable. Once you write the content, cannot erase and rewrite it again.
DVD-RW
We can use to read, write, rewrite and erase. Here, RW stands for rewritable.
Classification Based on the Capacity
The various types of DVDs based upon its capacity are:
| Nos | Types | Capacity of Storage |
| 1. | Single sided with single layer | 4.7gb |
| 2. | 单站在双层 | 8.5 to 8.7gb |
| 3. | Double sided with single layer | 9.4gb |
| 4. | Double sided with double layer | 17.08gb |
Classification Based on the Physical Measurements
The various types of DVDs based upon its Physical size are:
12cm :
This is the most common and preferred size used to store software,operating systemsand movies.
8 cm :
We can generally use it for small size devices like video cameras, portable music players, etc.
Formats
As we know that the DVD full form stands for digital video disc and later called digital versatile disc. The MPEG-2 file and compression format is used on it. MPEG-2 images have four times the resolution of MPEG-1 images and may be supplied at 60 interlaced fields per second, with each image frame consisting of two fields.
The design of formats are as follows:
DVD-Video
This is a format for full-length movies to play on a television set.
DVD-ROM
This is a type of computer drive and disc. In most cases, the DVD drive can also play CD-ROM and DVD-Video discs.
DVD-RAM
It is a rewritable version.
DVD-Audio
CD is the replacement format of DVD-Audio.
Some of the Recordable Formats
- DVD-RAM
- DVD-RW
- DVD+RW
- DVD+R
- DVD-R for General
- DVD-R for Authoring
Advantages
Some of useful advantages are:
- They have a high data stability.
- Provides large storage capacity such as 4.7 to 9 GB
- Gives good picture and sound quality
- Best options to storage videos and audios
- Price is comparatively less.
- Benefits in storing data on both sides of the Digital Versatile Disc, unlike CD one.
Disadvantages
Along with several positive features, there also some disadvantages.
- Movies and software will take years to become readily available.
- You cannot do direct recordings.
- Built-in copy protection and regional lockout facility.
- There is use of Digital compression. Poorly compressed audio or video may sound blocky, fuzzy, harsh, or hazy.
- It may reduce the dynamic range of the audio downmix process for stereo/ Dolby surround.
- Don’t support HDTV completely.
- Some performances of DVD players may not be able to read the content of CD-RS. Current Digital Versatile Disc players in the system can’t play in reverse at its normal speed.
- It is delicate, breakable or damage.
Frequently asked questions:
State the difference between DVD and CD?
A DVD and a CD have the same physical appearance. The data is read by a laser on both sides of the discs, which are the same size and having labelled and unlabeled side. However, as stated in the introduction, Digital Versatile Disc technology permits the same-sized disc to carry significantly more data than a CD.
Is there a DVD drive in my computer?
Today’scomputersno longer use this drive. Examine the front of your computer to see if it contains a DVD drive. A slot or tray that opens on the front of the computer to view a Digital Versatile Disc should be present. If you can’t see a DVD drive, look through your computer’s drives to check if your operating system recognizes one.
Does the DVD drive read the CD?
Yes, both CDs and DVDs are readable by all Digital Versatile Disc drives in the computer. With the help of DVD burner, you can also write on CD- RWs, CD- Rs and writable DVDs also.
How to open and close a DVD ROM drive?
The tray eject button on the front of a DVD-ROM drive can be pressed to open it (pictured right). Press the eject button again, or gently push on the front of the tray in some circumstances, to close it. Sometimes the eject button will not work then you can use my computer to open and eject the tray.
What DVD player should I acquire for my computer to watch movies?
VLC is a free and open-source media player for Windows, macOS, and Linux. On Windows machines, however, you can play most Digital Versatile Disc with Windows Media Player.
Author’s View:
As we all know, a Digital Versatile Disc is a type of compact disc capable of storing a large amount of data, particularly high-resolution audiovisual information, so once you’ve compared your data storage alternatives, there’s no one size fits all method.
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