Thinking of Doing a DVD?
DVD - replicated or "pressed", Digital Versatile (or Video) Disc
This is the movie that you buy at WalMart on DVD. These come in several formats but for the most part, they will all play in the set-top or computer DVD player. Normally, replication runs for DVDs have a minimum quantity of 1,000 to 2,500 pieces. What about smaller runs? There are DVD recordable discs on the market but this is where you need to make an informed choice as to the standard to employ.
If you want to author and distribute your own copy protected (CSS) DVD movies, it requires that your have an Authoring ("A") version of both the recorder and media. The Authoring version of the recorder will cost in the $3,000 to $5,000 dollar range, the media is over $20 per disc. You'll also need software that lets you build the DVD with all the different play back options, menus, and features your disc requires.
If your interest lies not in "studio-like" CSS protected movies but in other video fields (such as training, documentary and other types of video) or data publication (such as software releases, databases, archives and backups) or some combination of the two, then DVD General ("G") is probably the right choice. A DVD General Drive costs as little as 1/10 that of an authoring drive and the "G" discs are a fraction of the cost of the "A" discs.
So what's the difference between DVD(A) and DVD(G) exactly? The DVD(A) format has some features that have been carefully removed from the DVD(G) format. DVD(A) drives can write DDP headers (Disc Description Protocol), Region Coding information, Marcovision bits (to protect against DVD to VHS copying) and instructions that indicate to a mastering house that CSS is desired on the final product. All of this put together means that DVD(A) systems can produce Cutting Master Formatted discs that replication houses can use to press copies. This was done both to prevent DVD(G) drives from copying the latest Blockbuster movies and to collect royalties on all of the above listed copy protection technologies. (Hence the tenfold increase in price for a DVD(A) system.)
Do you remember the Beta versus VHS war? If you do you'll find the DVD recording war similar except, instead of two options, there are five formats competing to be "the recordable standard." What this means to you is that your choice could make your project unusable by others. The formats doing battle are the following: write-once DVD-R and DVD+R (referred to as "plus R") and re-writable DVD-RW, and DVD+RW (again, "plus RW") and DVD-RAM.
This format is similar to a single platter, removable hard drive. Once used by Apple in some of their machines they have since switched to one of the other formats. The DVD-RAM's strong point is the number of times that it can be re-recorded as many as 100,000 times vs. 1,000 times for other rewriteable DVD standards. Incompatible with both DVD players and the other recordable formats, and slower than all of them, it looks as if this will be the first format to disappear in favor of more compatible standards. If a hard-drive like technology is required, your best bet is to buy either a USB hard drive or the faster, more compatible DVD+RW.
DVD-R and DVD-RW
The recordable (DVD-R) and the rewriteable (DVD-RW) formats were developed by Ricoh, Pioneer and some other manufacturers in the DVD Forum. This format has no built in random access capability. This means that they are truly 'write once'. Even if they are not filled up during the first write session, they cannot have additional data added later. Once the DVD-R is written to, it is closed and can never be written to again. The DVD-RW must first be erased of all content before it can be written to again.
DVD+R and DVD+RW
Developed by Sony, Philips, HP and other companies, this competing standard was developed to be more compatible with consumer's storage requirements. These formats add the much needed random access capabilities to DVD writeable formats. The DVD+R can have data added to it in many separate sessions. The DVD+RW functions in a nearly identical fashion to the DVD-RAM drives only much faster. It also retains the ability to be read by nearly all DVD-ROM drives and Set-Top boxes.
The major difference in these formats is how the recorders find and utilize information encoded onto the discs. The good news is that once you make your discs (or have dataDisc do it for you), normally any available DVD reader will be able to read what's been recorded. All of the above formats discussed in this tech-tip with the exception of DVD-RAM are readable in most of the DVD hardware on the market today.
In summary, if you're going to do a DVD, datadisc can guide you through the maze of options as well as duplicate your discs in small or large quantities for maximum compatibility with your customer's hardware.
By Al Foster & Jon Beckmann