Producing such a disc may sound like a straightforward task, but ensuring that both recordable layers have the same optical properties as stamped pits was a monumental feat. Even after carefully tweaking parameters like the precise depth and shape of the recorded "pits," the thickness and chemical composition of each dye layer, and the ability of the metallic coatings to reflect or transmit light, first-generation DL media are still subject to constraints. Both formats, for example, require that data on Layer 0 must be recorded before the corresponding position on Layer 1 can be burnt.

Recordable dual-layer media won't single-handedly revolutionize the DVD industry. But the technology is a giant leap in the continuing effort to make personal DVD recording flexible enough to handle any DVD application.

Data organization on a DVD

The top level of data organization on a DVD is a volume. The volume is made up of the UDF Bridge File System, a single DVD-Video Zone, and the DVD-Others Zone.


The DVD specification defines a single file format for all disc formats - the Universal Disc Format (UDF). UDF ensures any file (computer data, audio or video) can be accessed by any player, computer or DVD-Video player. It overcomes the incompatibility problems CD suffered, when a new standard had to be written when a new application, such as multimedia, interactivity, or video emerged.

UDF brings all file formats together into one.

DVD-Video discs use only UDF (not ISO 9660) with all required data specified by UDF and ISO 13346 to allow playing in computer systems. The DVD-Video files must be no larger than 1 GB in size and be recorded as a single extent (ie in one continuous sequence). The first directory on the disc must be the VIDEO_TS directory containing all the files. All filenames are 8.3 format.

The DVD-Video Zone contains all the data elements for the set-top video title. It begins with a Video Manager, which is a master directory for all the data elements on the disc.
The Video Manager usually contains an introductory piece of video and audio (e.g. an opening logo), and title menu to navigate the title sets, which follow the Video Manager.

DVD-Video also includes a "DVD Others Zone" on the disc. This area is used to store standard computer files. In other words, the disc can be played back on both a DVD-Video player, and a PC with a DVD-ROM player.

• Title Sets
  The top level of this layer is made up of the titles.
• Program chains and programs
  Each title contains up to 999 program chains, and each program chain contains 0 to 99 programs, which are ordered collections of pointers to cells. The physical and logical layers then converge at cell level. The program chain links cells together and indicates which order to play the programs and cells. Programs within a program cell can be played sequentially, randomly or shuffled. DVD-Video playback is directed from Program Chains. The program chain instructs the DVD player on how the Video Objects should be played back, under what conditions, and in what order. Program chains are used by DVD players to navigate through the disc.
• DVD data streams
  Contain control information, such as the video display format (NTSC, PAL), aspect ratio, language, audio and subpicture selection, and information for parental management. They also contain search and navigation information.

Menus interact with the program content.
Systems Menus are available through the press of a button on the remote control:

• Title Menu - resides in the Video Manager and accesses Titles on the disc.
• Root Menu - resides in each Video Title Set, and can access Video Titles.
• Audio, Angle and Subpictures Menus - also reside within each Video Title Set, and are used to change the audio stream, video angle and subpicture stream.

When a systems menu is accessed, the DVD player remembers exactly where in the video stream it was playing, and can return to that location after the viewer has finished using the menu .

The different DVD formats

• DVD:
  Short for digital versatile disc or digital video disc, a type of optical disk technology similar to the CD-ROM . A DVD holds a minimum of 4.7 GB of data, enough for a full-length movie. DVDs are commonly used as a medium for digital representation of movies and other multimedia presentations that combine sound with graphics.The DVD specification supports disks with capacities of from 4.7GB to 17GB and access rates of 600KBps to 1.3 MBps . One of the best features of DVD drives is that they are backward-compatible with CD-ROMs, meaning they can play old CD-ROMs, CD-I disks, and video CDs, as well as new DVD-ROMs . Newer DVD players can also read CD-R disks. DVD uses MPEG-2 to compress video data.
• DVD-R
  Short for DVD-R ecordable , a recordable DVD format similar to CD-R . A DVD-R can only record data once and then the data becomes permanent on the disc. The disc can not be recorded onto a second time. There also are two additional standards for DVD-R disks: DVD-RG for general use, and DVD-RA for authoring, which is used for mastering DVD video or data and is not typically available to the general public. DVD-R, DVD-RW and DVD-RAM are supported by Panasonic, Toshiba, Apple Computer, Hitachi, NEC, Pioneer, Samsung and Sharp. These formats are also supported by the DVD Forum.
• DVD+R
  DVD+Recordable defines a standard for recordable DVD drives and media defined by the DVDRW Alliance. Often called "plus R", the format is write once (compared to DVD+RW wich can be erased and rewritten). The single sided discs can hold 4,700,000,000 bytes (4.38 Gigabytes at 1024 bytes to the kilobyte) with double sided discs holding twice as much. This format competes with the DVD Forum DVD-R specification.
• DVD-RW
  Short for DVD-R eWritable , a re-recordable DVD format similar to DVD+RW . The data on a DVD-RW disc can be erased and recorded over numerous times without damaging the medium. DVD-R, DVD-RW and DVD-RAM are supported by Panasonic, Toshiba, Apple Computer, Hitachi, NEC, Pioneer, Samsung and Sharp. These formats are also supported by the DVD Forum.
• DVD+RW
  Short for DVD+R eWritable , a re-recordable DVD format similar to CD-RW . The data on a DVD+RW disc can be erased and recorded over numerous times without damaging the medium. DVD+RW and DVD+R formats are supported by Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha and others.
• DVD-RAM
  A DVD format wherein DVD-RAM discs can be recorded and erased repeatedly but are only compatible with devices manufactured by the companies that support the DVD-RAM format. DVD-RAM discs are typically housed in cartridges. DVD-R, DVD-RW and DVD-RAM are supported by Panasonic, Toshiba, Apple Computer, Hitachi, NEC, Pioneer, Samsung and Sharp. These formats are also supported by the DVD Forum.
• DVD-ROM
  A new type of read-only compact disc that can hold a minimum of 4.7GB ( gigabytes ), enough for a full-length movie. The DVD-ROM specification supports disks with capacities of from 4.7GB to 17GB and access rates of 600 KBps to 1.3 MBps . One of the best features of DVD-ROM drives is that they are backward-compatible with CD-ROMs. This means that DVD-ROM players can play old CD-ROMs, CD-I disks, and video CDs, as well as new DVD-ROMs. Newer DVD players can also read CD-R disks. DVD-ROMs use MPEG-2 to compress video data.
• DVD-10
  DVD-10 (12 cm, DS/SL) 8.74 gig (9.40 BB), about 4.5 hours
• DVD-14
  DVD-14 (12 cm, DS/ML) 12.32 gig (13.24 BB), about 6.5 hours
• DVD-18
  DVD-18 (12 cm, DS/DL) 15.90 gig (17.08 BB), over 8 hours
• DVD-5
  DVD-5 (12 cm, SS/SL) 4.37 gig (4.70 BB) of data, over 2 hours of video
• DVD+R DL
  DVD+R DL or called DVD+R9 is a Dual Layer writeable DVD+R. The dual layered discs can hold 7.95 GB or around 8 540 000 000 bytes (called DVD-9)
• DVD-9
  DVD-9 (12 cm, SS/DL) 7.95 gig (8.54 BB), about 4 hours (a DVD-9 is basically two pressed plastic DVD-5s pressed together, they are not burned)

When do I need to change the Book Type of my DVD?

For a DVD player or drive to identify what kind of disc is loaded, it reads the "Book Type Field" found in the lead-in section of each DVD disc. These few bits, commonly referred to as "compatibility bitsettings" tell the drive which low-level format specification the media conforms to, such as DVD-ROM, DVD+R or DVD+RW. The specifications for each format are written in a "book" which describes the physical and logical characteristics of a specific format. If you're thinking about making a DVD product, you can buy the official DVD specification books from Toshiba for $5,000 and after signing a non-disclosure agreement.

Most DVD players will read a DVD+RW or DVD+R disc without any problems, however a few of them report a disc error when a disc is loaded that is not marked as a "DVD-ROM" disc in the compatibility bits. Ususally, these players are physically able to read the disc (since DVD+RW reflectivity is identical to that of a dual layered DVD-Video disc, which all players must be capable of reading), but their compatibility problems are due to different interpretations of these bits in the various firmware versions. In most cases, the problem can be solved by updating the firmware.

When a firmware fix is unavailable, or when you want to increase the playability so the disc will play in more players, you can change the "book type" from DVD+R/DVD+RW to a DVD-ROM. This is what's called "changing the compatibility bitsettings". With a DVD+RW PC drive, you'll need a special utility program to accomplish this. DVD Decrypter has a feature located in the lower right corner of the application's ISO write mode window that allows the setting of book type on specific DVD-RW drives. DVD Shrink has an option for creating a "Book type DVD-ROM" located on the Burn Settings tab in the Backup DVD menu.

Note: You only need to apply this special compatibility setting to a disc if you encounter reading problems with your DVD equipment. Players and drives that need the DVD-ROM setting for DVD+RW discs are marked with (cs) in the rpc1.org compatibility list

DVD+RW drive vendors advise you not to apply these setting unless you specifically need so in your situation, however no DVD drive or player should encounter problems with a disc marked as "DVD-ROM", as this is the default value for read only discs .

DVD Write types

• CAV = Constant Angular Velocity, the DVD is written at a constantly increasing speed.
• CLV = Constant Linear Velocity, the DVD is written at a constant speed.
• ZCLV = Zone Constant Linear Velocity, the DVD is divided into zones. After each zone the write speed is increased.
• PCAV = Partial Constant Angular Velocity, the DVD is being written at an increasing speed until a certain speed. After this speed it will not increase anymore.

How do I enable the "DMA" mode in Windows?

Basically, DMA or Direct Memory Access is a system that allows devices in your computer to transfer data directly to and from RAM without having to use the CPU as an intermediary. This boosts the performance of your PC significantly as not only the device from which the data is being read responds quickly, but also leaves the most important component, the CPU, free for other critical operations. However, the UDMA or the Ultra direct memory access is further advancement over the DMA technology that uses even higher data transfer rate thereby boosting the overall performance of the PC. Read an illustrated, step by step guide.

• In Windows 98/ME:
  Right click My Computer and choose Properties. Click Device Manager. Click the "Disk drives" tab. Double click any hard drive icons (you may have more than one). Click the "Settings" tab. If you see a DMA checkbox, the drive supports DMA transfers. Click the checkbox and close the window. Do the same for your CD-ROM drive (or drives, if you have more than one). When you're through, Windows will tell you to reboot. After you start up Windows again, go back to the Device Manager and see if the checkboxes are still checked. If any of them are not, Windows is telling you that the drive in question does not actually support DMA properly. (If that's the case, you're out of luck.)
• In Windows 2000/XP:
  To enable the DMA setting, simply right click on the My Computer icon and then from the drop-down menu, click on the properties option. This will open the system properties dialogue box on your computer screen. Now select the hardware tab and then click on the Device Manager button. In the Device Manager window, click on the IDE ATA/ATAPI controllers branch to open it. From the corresponding window, double click on the secondary IDE channel. This will open the secondary IDE channel property box on your computer screen.
  In this box, click on the Advanced Settings tab. Here you'll find the details regarding the DMA or Ultra DMA settings mode. If the mode is not set to the DMA or Ultra DMA, then you should select Auto Detection from the Device Type drop-down list and then click OK. Then, close the open window and restart your PC.

What are the PIO and DMA modes?

• PIO (Programmed I/O): The CPU controls all action of data transfer I/O. (This increases CPU loading)
• DMA (Direct Memory Access): Uses the Main Memory to control the action of data transfer I/O. (This decreases CPU loading)

Mode	Cycle Time (nanoseconds)	Max Data Transfer Rate	Standard
PIO Mode 0	600 ns	3.33 MB/sec	ATA
PIO Mode 1	383 ns	5.22 MB/sec	ATA
PIO Mode 2	240 ns	8.33 MB/sec	ATA
PIO Mode 3	180 ns	11.1 MB/sec	ATA 2
PIO Mode 4	120 ns	16.7 MB/sec	ATA 3
DMA, Single Word, Mode 0	960 ns	2.11 MB/sec	ATA
DMA, Single Word, Mode 1	480 ns	4.22 MB/sec	ATA
DMA, Single Word, Mode 2	240 ns	8.33 MB/sec	ATA
DMA, Multiple Word, Mode 0	480 ns	4.17 MB/sec	ATA
DMA, Multiple Word, Mode 1	150 ns	13.3 MB/sec	ATA 2
DMA, Multiple Word, Mode 2	120 ns	16.7 MB/sec	ATA 3
Ultra DMA Mode 0	235 ns	16.7 MB/sec	ATA 4
Ultra DMA Mode 1	160 ns	25 MB/sec	ATA 4
Ultra DMA Mode 2	120 ns	33.3 MB/sec	ATA 4, Ultra ATA
Ultra DMA Mode 3	90 ns	44.4 MB/sec	ATA 5
Ultra DMA Mode 4	60 ns	66.6 MB/sec	ATA 5, Ultra ATA/66
Ultra DMA Mode 5	40 ns	100 MB/sec	Ultra ATA/100

KB/sec at burn speed setting

Write speed	Data Rate
16X	22,160 KB/s
12X	16,620 KB/s
8X	11,080 KB/s
6X	8,310 KB/s
4X	5,540 KB/s

DVD Tutorials home page

Back to Burning your first DVD

Top of the Page