DVD FAQ

DVD FAQ

First of all, what is DVD?
DVD stands for "digital video disc". Some people argue that DVD stands for "digital versatile disc". It doesn't matter at all actually. What matters is to remember: DVD is the latest generation of optical disc storage technology.
We can regard DVD as a much better version of CD - much bigger and faster. DVD can hold cinema-like video, better-than-CD audio, and computer data. DVD has widespread support from all major electronics companies, computer hardware companies, and movie and music studios. Eventually, it seems that DVD has been replacing videotape, LD, CD-ROM, very quickly recently.
DVD uses MPEG-2 compression to store videos.

What's so good about DVD?
DVD has become the most popular format for video makers. There must a reason, right?
A single-side, single-layer DVD can hold 4.7GB data which means over 2 hours of high-quality digital video.
Support for wide-screen movies on standard(4:3) or wide-screen(16:9) TVs .
Up to 8 tracks of digital audio (for multiple languages, DVS, etc.), each with as many as 8 channels.
Up to 32 subtitle/karaoke tracks.
Up to 9 camera angles (different viewpoints can be selected during playback).
Menus and simple interactive features (for games, quizzes, etc.).
Compact size (easy to handle, store, ship and duplicate).
Parental lock (for denying playback of discs or scenes with objectionable material).
Copyright protection (stopping duplication) and regional lockout (preventing playback of certain discs in certain region/country).
Yet, most discs do not contain all features (multiple audio/subtitle tracks, parental control, etc.), as each feature must be specially authored.
Most DVD players only support certain set of features as well.

What's the capacity of DVD?
There are two physical sizes: 12 cm (4.7 inches) and 8 cm (3.1 inches), both 1.2 mm thick. A DVD disc can be single-sided or double-sided. Each side can have one or two layers of data. A single-sided, single layer DVD disc can hold 4.7GB data or more than 2 hours of video. A double-sided, double layer DVD can hold 17GB.
You will use 12 cm, single-sided, single layer disc to burn your DVD videos.

How's the quality of DVD video?
The simple answer is, DVD video is amazingly great. It's capable of producing near-studio-quality, better-than-LD videos.
The not-so-simple answer is, it depends on many factors. Poor video source, bad cables, improper color correction, electrical interference, compression rate...all these will affect your final result.
From my own experience, on a properly configured system, the difference between end DVD video and its source is not noticeable to not-so-experienced-eyes. If you find something strange, it's not because of the DVD burning in 99% of cases.

Confused by all the various DVD recording formats?
Currently, there are 7 DVD formats:
DVD VideoFor viewing movies and other visual entertainment. This is the format used by Hollywood.
DVD-ROMIts basic technology is the same as DVD Video, but it also includes computer-friendly file formats. It is used to store data.

DVD-RAMThis makes DVD a virtual hard disk, with a random read-write access. Originally a 2.6GB drive, its capacity has increased to 4.7GB-per-side. Double sided DVD-RAM media is now available with a 9.4GB capacity. It can be re-written more than 100,000 times. DVD-RAM disks can NOT be played back in set top or computer DVD players. You must have a DVD-RAM drive to playback DVD-RAMs.

DVD-RIts capacity is 4.7GB. As with CD-R, users can write only once to this disk. DVD-R disks can be played back in most set top & computer based DVD players.
DVD-RWIts read-write capacity is 4.7GB per side. It can be re-written up to about 1,000 times. DVD-RW is an extension of the DVD-R format and forum. Like DVD-R, DVD-RW disks can be played back in most set top DVD and computer based DVD players.

DVD+RWIts read-write capacity is 4.7GB per side. It can be re-written up to about 1,000 times. DVD+RW disks can be played on most set top DVD and computer based DVD players.
DVD+RA single write version of DVD+RW.
DVD-R/RW is mainly supported by Pioneer, Yamaha, Ricoh, and Panasonic.
DVD+R/RW is supported by Philips, Sony, HP, Mitsubishi Chemical, Thompson, Dell.

The companies in each camp (dash and plus) are fighting hard to become the worldwide standard. The dominant format will then generate billions of dollars in licensing & royalties to the companies behind it. The market will determine which of them succeeds, or if they end up coexisting or merging.
Are these DVD formats compatible with each other?
Unfortunately, no.

DVD-R/RW disks may or may not be read by DVD+R/RW hardware and vice versa. But both the dash and plus camp claim to have the better compatibility with set top DVD players.
All of the various competing camps are fighting to become the new industry standard. The way they will accomplish this is by making sure the disks you make using their burners play in as many DVD players as possible. I would say, with a high degree of certainty, that any DVD-R/RW and DVD+R/RW disks you make will work in just about every DVD player currently on the market.

Yet, the DVD specification is complex and open to interpretation. DVD authoring is also very complex. As with any new technology, there are compatibility problems here and there. Check Film Vault for reported compatibility problems before buying.

source: http://www.aboutvideoediting.com/articles/DVD-faq.shtml