Don't Be Stumped By DVD Standards

This article has been published with permission from InterVideo, Inc. It may not be published in any form outside without exclusive permisson from InterVideo, Inc.

DVD is the hottest thing to hit consumers, well, ever. Consumers are snatching up DVD movies like "Shrek" in record numbers, and even mordibund TV series like "Twin Peaks" and "M*A*S*H" are finding new life as DVDs. Home DVD players are selling at a faster rate than the radio, Internet or even television was adopted. Virtually all new computers come with a DVD drive allowing tens of millions of consumers the ability to play DVDs on a computer. But the biggest change is yet to come.

2002 is the year a number of manufacturers have, or will, release DVD burners, allowing consumers the ability to make their own DVDs with a computer for the first time ever. However, intrepid DVD creators should proceed with caution. DVD is a new technology and not all devices support the same standard. In fact, there are a number of competing formats for making your own DVDs making it possible that the DVD you create on your computer may not play in your living room. This article will arm you with the information you need to know to keep that from happening. But pay close attention, in a moment the acronyms are going to start flying around like a box of nails caught in a tornado.

The easiest way to understand the subtleties of DVD technology is to divide the discussion into 3 parts: application formats, writable formats and DVD drives.

Application formats

Let's begin with application formats. The good news is that every DVD movie that you buy or rent is in a single application format called DVD-Video. All DVD players and DVD drives can play DVD-Video. Now the bad news, you might create your own DVD-Video movie and it might not play in your DVD player. Sounds odd, doesn't it? Let's move on to writable formats.

Writable formats

Although DVD disks look like CDs, they are not the same thing. The biggest difference is that a DVD can hold much more information than a CD. Most CDs hold 650 or 700 megabytes of data, movies or music. Most DVDs hold 4.7 gigabytes, or about 7 times more information than a CD. This extra capacity allows entire Hollywood movies to fit on a single disk. If you want to create your own DVD movie, you will need to get a writable version of one of these DVD disks. This is where it starts to get complicated.

Imagine if there were 5 different kinds of VHS tapes and they all looked identical but were not -- that is basically where the DVD standards world is right now. There are essentially 5 versions of writable DVD that you need to understand. They are: DVD-R, DVD-RAM, DVD-RW, DVD+RW, and DVD+R. The distinctions are actually based on how the data is written to and read from the disk, and this differentiation is difficult to translate to the physical world, however one example might be language.

Imagine if the entire world agreed on a single language for all written documents, say English. In the United States we would continue to create English documents and books in which one reads left to right. But another country might prefer to write and read English right to left. And yet another, top to bottom, and so on until the effect became that although all documents were created in a single language, it would be very difficult for a person from one country to read a document from another country. DVD recording is in a similar state of confusion. DVD is such a nascent technology that these issues have yet to work themselves out, so you have no choice other than understanding them all. One easy way to think about the formats is as 5 completely different kinds of DVD disks.

First, let's divide the formats up. The first thing to note is that DVD-R and DVD+R disks can only be recorded once. You only get one chance to record your DVD movie to this kind of disk It's like pouring cement, once it is done you'll need to destroy it to change it. Further, DVD-R discs come in 2 types: DVD-R(A), for "authoring," and DVD-R(G), for "general." Both DVD-R and DVD+R discs will play in most DVD players, even older ones. So if you put your movie on this kind of disk there is a high probability that it will play in your living room. However, DVD-R(A) drives can not record to DVD-R(G) disks, and vice versa.

There are also DVD formats that can be recorded more than once. DVD+RW, DVD-RW and DVD-RAM disks can all be recorded thousands of times. If you don't like how your DVD movie turns out, you can record a new version right on the same disk. These disks are more like painting a wall, if you don't like the color you just put on a new coat.

Each of these rewritable formats are a little different. DVD-RAM, for instance, was created for storage of computer data -- like backing up your hard drive. If you want to get a DVD writer to back up computer data, DVD-RAM is a solid option. However, if you plan to make your own DVD movies, one of the other formats may be better suited for that activity. Most DVD players can't play DVD-RAM disks.

The DVD-RW and DVD+RW formats are both good for making DVD movies but are essentially engaged in a Beta versus VHS-type battle. The consumer market will ultimately determine which format wins or they end up combining into a single standard, but it is important to understand that neither is yet a universal standard. Another thing to note is that many DVD players won't play any kind of rewritable disk. Most of the newer players will play these kinds of disks, but if you have an older DVD player it may not. In general, the newer your DVD player, the more likely it is to play all the recordable formats. There are web sites like, and that list compatible players and formats, but these are not unabridged resources either. Use them as a general guide.


That covers the basic DVD writable formats, the last point of concern is the DVD drive itself. This is the part of your computer that will actually record your data or movie onto the DVD disc. Thankfully, if you have made it this far you are almost home. The different types of DVD drives basically break down into the same formats as the DVD writable formats. Therefore, there are DVD-RAM drives, DVD-R drives etc. on down the line. It is also increasingly likely that DVD burners will come with the ability to record to more than one format, for example a manufacturer may offer a DVD+R/RW drive meaning that it can record both DVD+R and DVD+RW discs. When considering DVD media (the actual silver discs) and DVD burners, make sure that both the discs and drive are the same format. Below is a table of what types of DVD media work in different DVD drives:

Living Room DVD PlayerComputer DVD-R(G) DriveComputer DVD-R(A) DriveComputer DVD-RW DriveComputer DVD-RAM DriveComputer DVD+RW Drive
DVD-R(G) DiscsUsually playsPlays and writesPlays but does not writePlays and usually writesPlaysPlays
DVD-R(A) DiscsUsually playsPlays but does not writePlays and writesPlays but does not writePlaysPlays
DVD-RW DiscsUsually playsPlaysPlaysPlays and writesUsually playsUsually plays
DVD+RW DiscsUsually playsUsually playsUsually playsUsually playsUsually playsPlays and writes
DVD+R DiscsUsually playsUsually playsUsually playsUsually playsUsually playsPlays and writes
DVD-RAM DiscsUsually does not playDoes not playDoes not playDoes not playPlays and writesDoes not play

That is about as simple as it gets, at least for now. You'll probably want to print out this article and consult it when you buy your DVD burner, but let's review.

Making the choice

Step one: Decide what you want to use your DVD burner for. If you want to back up computer data a DVD-RAM burner is a good choice. If you want to record movies and music choose another kind of burner.

Step two: Decide where you will be watching your DVDs. If you plan to send your homemade DVD movies to friends and relatives with older DVD players, you will want to make sure you get a DVD-R or DVD+R burner. If you plan to watch your DVD movies on a computer or a newer DVD player any format will likely do. Again, these are general guidelines and there are lots of exceptions. Check the web and do your homework.

Step three: Match em up. Remember the children's clothing brand Garanimals? If a shirt had a lion on it, you had to find a pair of shorts with a lion on it. If you got a Garanimal shirt with a lion on it and shorts with a fox then they would be different sizes and would not match. DVD is the same way. You need to make sure that your DVD media and DVD drive are the same.

All of these DVD acronyms can be pretty intimidating, but now you know better and as G.I. Joe used to say, "Knowing is half the battle." Not to mention this is only going to get easier and easier as the standards work themselves out.

The last point is this: it is worth it. The learning curve pays off the first time you sit down on your couch with your remote control and popcorn to watch a DVD that you (or your your kids) made, and the alphabet soup of DVD will give way to the warm glow of a job well-done. Have fun.

Honda Shing is Chief Technology Officer for InterVideo which makes WinDVD, the world's most popular software DVD player. InterVideo ( also makes other audio and video software and will soon release WinProducer 2 DVD, a program to edit and burn your own DVDs.

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Written by: Jari Ketola