DVD Compatibility Test - Maxell Canada

ROUNDUPWith the release of set-top DVD recordersfrom Panasonic, Pioneer, and others, recordableDVD is rapidly becoming a mass-marketproduct. Computer-based DVD burners arereadily available for less than $400, and settopunits can be bought for less than $1000.Combined with inexpensive DVD authoringtools from companies such as Apple, PinnacleSystems, Sonic Solutions, Ulead, and others,affordable systems for making your own DVDdiscs are becoming a reality for many consumers.But compatibility issues are growingexponentially.Unfortunately, there is trouble in recordableDVD paradise. As with most new technologies,recordable DVD has a compatibilityproblem. This compatibility problem hasthree main factors—the DVD formats (e.g.,DVD-R, DVD+RW, DVD-RW), the DVD blankmedia manufacturers (e.g., Maxell andVerbatim), and the DVD players (e.g., Pioneerand Sony)—that have complex permutations.This article is anattempt to bring sanityto how compatibility isreported for recordable DVDmedia on consumerDVD-Video players.The purpose of this article is to make DVDproducers, vendors, and consumers aware ofthe compatibility issues for recordable DVD.The compatibility of replicated DVDs, burnedfrom glass masters in high volumes at largeDVD replication houses, is outside the scopeof this story. I will explore the issues thataffect DVD producers who burn smaller runsthemselves.I’ll provide recommendations on how toavoid problems when you record DVD discsand how to attain the widest compatibility soyour DVD can be watched by as many peopleas possible. Then I’ll wrap up with a few generalguidelines to help you get the most outof recordable DVD.A brief overview ofrecordable DVD technologyLet’s start by taking a look at the differenttechnologies used to make a recordable DVD.There are currently five different types ofrecordable DVD products on the market.These products are DVD-R for Authoring,DVD-R for General, DVD-RW, DVD+RW, andDVD-RAM. A sixth product, DVD+R, shouldbe widely available within the nextfew months. Each of these recordable DVDtechnologies has its own strengths and weaknesses.DVD-R for Authoring, DVD-R for General,and DVD+R all use organic dyes that are sensitiveto an infrared laser. DVD-R for General andDVD+R discs are recorded using a 650nm(nanometer) laser, while DVD-R for Authoringdiscs are recorded using a 635nm laser. Whenthe organic dye is exposed to a low-powerinfrared laser, it is permanently changed andthe data is recorded onto the disc. Therewritable formats—DVD-RW, DVD+RW, andDVD-RAM—use phase-change materials. Thereare two different power levels used for writingand erasing data on a phase-change disc. Thehighest power level causes the surface of thematerial to become less reflective, and a lowerpower level causes the material to becomemore reflective. Phase-change-based recordableDVD media can be rewritten more than 1000times, but the organic dye material used inDVD-R and DVD+R media can only be writtenonce.Potential compatibility problemsSeveral different compatibility problems canoccur between a recorded DVD disc and aconsumer DVD player. These problemsinclude physical, logical, and applicationincompatibilities. The DVD specificationstates that single-layer discs should have areflectivity between 45 percent and 85 percent,and dual-layer discs should have areflectivity between 18 percent and 30 percent.The first potential problem with recordableDVD media is if their reflectivity fallsoutside the specified ranges.The DVD specification also defines severallogical parameters that are important forrecordable DVD media. These parameters arestored in the header area of each data sectoron the disc, and they include sector type format,tracking method, reflectivity, layers, anddata type information. Each logical parametermust be set correctly for a recordable DVDdisc to work properly.Application-level compatibility problemsare generally related to the average and burstdata rates of the content stored on the disc.In theory, any recorded DVD disc that complieswith the DVD specification should workfine on all consumer DVD-Video players.However, in practice, recorded DVD discswith high average or burst data rates, or withdata stored at or near the outer edge of thedisc, are more likely to exhibit playback compatibilityproblems.Several differentcompatibility problems canoccur betweena recorded DVD discand a consumerDVD player. Theseinclude physical,logical, and applicationincompatibilities.Physical, logical, and application compatibilityproblems can manifest themselves in anumber of different ways. Many consumerDVD-Video players will fail to mount arecorded DVD disc. When this happens, theplayer usually displays an error message indicatingthat the disc is damaged, has thewrong region code, or, in some cases, a diagnosticcode. Other typical problems includevideo artifacts, audio dropouts, and navigationproblems that prevent portions of thedisc from being accessed. In some cases, aDVD-Video player may lock up while playing arecorded DVD disc.What is compatible?One of the most frustrating things that canhappen to a DVD developer is to send recordeddiscs to clients, friends, or relatives, and thediscs fail to play properly on their systems.Many developers know enough about potentialcompatibility problems that they tell theirclients or friends to use a compatible player inorder to use the disc they send them, but whatcompatible means isn’t always clear.A number of Web sites—such aswww.vcdhelp.com/dvdplayers.php, www.apple.com/dvd/compatibility, and www.DVDMade-Easy.com—provide information about compatibleplayers. Unfortunately, the data