Learn more about: DVD-R DVD-RW DVD+R DVD+RW DVD-RAM DVD-R What is DVD-R?
The "R" in DVD-R stands for recordable or simply put - "write one time." DVD-R is the next generation of CD-R. Think of it as the larger capacity brother of CD-R. DVD-R is a write once single sided optical disc. It has the same physical size as a CD-R (12cm), but has higher data and track densities that give it about 7 times the storage capacity of a standard 650MB CD-R. DVD-R's current capacity is 4.7GB and a migration path up to 9.4GB has been established by using a double-sided disc. DVD-R is very similar to CD-R in that both use a dye-based material and lasers to write and store their data. Both are permanent write once formats. CD-R and DVD-R also share another important feature - compatibility. Like the read compatibility for CD-R provided by CD-ROM drives, DVD-R can be read back in most DVD ROM drives or DVD video players in the market, making it the ideal solution for high capacity data, video, or audio distribution. What are the two types of DVD-R?
There is a DVD-R for Authoring and DVD-R for General use. DVD-R Authoring media contains a unique feature important to the Professional user - Cutting Master Format or CMF. This enables Authoring media to be used as a direct replacement for DLT tapes when submitting a title for replication. This can save the creator valuable time and effort in the authoring process. General media does not contain this format. When recording, both discs must be written in their respective drives, (authoring media in an authoring drive and general media in a general drive). Once recorded, playback devices don't care what drives the discs were recorded in, and they can be read in either drive. It is important to note that CSS encrypted DVD video movies cannot be copied to either type of DVD-R media. What are the two methods of recording DVD-R?
"Disc at Once" and "Incremental Recording" are the two methods of recording DVD-R. Similar to CD-R recording, disc at once implies just that, the entire disc is recorded at one time. Once the disc is fully compiled it is finalized and then can be read in a DVD ROM drive or DVD Video player (depending on the content.) Incremental Writing is accomplished by writing data to the DVD-R at different times rather than all at once. Additional files can be added until the job is complete or the disc is full. Until the disc is finalized it cannot be read in DVD ROM drives or DVD Video players. How long does it take to record a DVD-R?
A complete first generation 3.95 DVD-R can be written in about 20 minutes. A complete second-generation 4.7GB disc can be recorded in about a ½ hr. What are the applications of DVD-R?
Due to its increased capacity vs. CD-R, universal compatibility, affordable cost of media, and drives, DVD-R is currently being used in several different markets and in many diverse applications. DVD is currently being used for medical images (cat scans, X-rays etc.), archival and long term storage of data, short run distribution of software, bank statements and credit card reports, training, advertising and marketing tools, Data conversion - from older outdated formats to DVD-R. What drives can write DVD-R discs?
DVD-R can be written by several different drives from several different manufacturers baring the DVD-R symbol. DVD-R discs can also be written by DVD-RW and DVD-Ram drives. Back to top
DVD-RW What is DVD-RW?
DVD-RW stands for DVD rewritable or re-recordable. It is one of the official formats endorsed by the DVD Forum. It has a capacity of 4.7GB, is recorded sequentially like a CD-R, but unlike a CD-R it can be overwritten 1000 times using phase change material instead of organic dye material. "RW" as it is also known, has a data storage life of 30-50 years. DVD-RW is basically the rewritable cousin of the DVD-R format from Pioneer. DVD-RW is very similar to CD-RW, just like DVD-R is similar to CD-R. DVD-RW discs can be read in most DVD ROM and DVD Video players. These discs do not use protective cartridges allowing them to be loaded into all drives and players. DVD-RW can also be used as an authoring tool for DVD titles. How is it written?
DVD-RW like its rewritable competitors DVD RAM and DVD+RW, utilize phase change material to record information to the disc. The writing drives laser heats the phase change surface thereby changing the materials reflective properties between crystalline (highly reflective) and amorphous (dull - non reflective.) The resulting light and dark spots are interpreted as data bits and then transferred to the attached computer. DVD-RW can be rewritten over 1000 times without media degradation. Data, video or audio can be written to a DVD-RW disc completely from start to finish which is called "Disc at Once". Information can also be written at various different intervals. This method is called "Incremental writing" Both methods require that the discs be "finalized" or closed before they can be read in A DVD ROM drive or DVD player. Some drives and players are confused by DVD-RW media's lower reflectivity (18-30%). They sometimes interpret this media as a dual layer disc and will not write or read it. What schemes does DVD-RW use for Copy Protection?
All DVD Recorders, DVD rewritable drives and their associated media can recognize encrypted content and will not allow the coping of this material. Just like the other rewritable formats, DVD-RW cannot be used to copy CSS encrypted DVD movies. This guards against pure digital copies of the original DVD video source material. DVD-RW also incorporates CPRM (Copy Protection for Recordable Media). CPRM prevents unauthorized recording of protected source material when using the (VR) Video Recording Format. If allowed by CPRM, some source material may be allowed to be copied one time. What applications are best suited for DVD-RW?
Because of its sequential format like a CD-R/RW, and broad compatibility with existing DVD players, DVD-RW main applications would be for video applications, such as recording and editing home video, downloading streaming video from the internet or computer backup applications. Rewritability and Random access make DVD-RW ideal for all data applications. Back to top
DVD+R What is DVD+R?
DVD+R is the write-once version of the DVD+RW format that has been developed in cooperation by Hewlett-Packard, Mitsubishi Chemical, Philips, Ricoh, Sony, and Yamaha. It currently has a single-sided capacity of 4.7GB, and is capable of storing up to 2 hours of MPEG-2 video. Like DVD+RW, DVD+R is a format that has not been approved by the DVD Forum, and therefore the DVD+R products do not bear the typical DVD logo. Instead, the DVD+RW Alliance has developed its own logo for the +R and +RW products. The DVD+RW Alliance claims that its format is the most compatible write-once DVD format, providing full compatibility with DVD Video players and DVD-ROM drives. How does DVD+R work?
DVD+R, like other write-once formats such as CD-R and DVD-R, uses a dye-based recording layer in which a laser is used to burn information to the disc. The information, once recorded (or "burned") into the dye, is permanent and cannot be altered or deleted. DVD+R records at speeds of 1x to 2.4x that of DVD Video. The Differences: DVD+R vs. DVD-R
DVD+R share similarities in that they are both write-once formats, they both have single-sided capacities of 4.7GB, they both need finalization after recording, and both can be used for either data storage or video applications. The major difference is that they are not interchangeable when it comes to recording. Because each format writes information to it's corresponding disc differently, DVD+R discs must be recorded in a +R computer drive or video recorder, and DVD-R discs must be recorded in a -R computer drive or video recorder. Once recorded, they share similar playback compatibility, and both will play back in a majority of existing DVD Video players. Another difference is that DVD-R consists of various formats (General and Authoring), sizes (3.95GB and 4.7GB), and versions (1.0, 1.9, 2.0). With DVD+R, there is one format, one size, and one version. Compatibility
DVD+R is designed to be compatible with computer DVD-ROM drives and consumer DVD Video players. This "2-way compatibility" ensures that a DVD+R disc will play back in both DVD-Video players and computer DVD-ROM drives (as long as they have MPEG-2 decoding capabilities), regardless of which type of drive it was recorded in. Once a DVD+R disc has been recorded and finalized, its characteristics comply with the specifications for DVD-ROM, ensuring compatibility across all platforms. Supporting Recorders
Since DVD+R was released as an enhancement to the original DVD+RW specification, there are some early drives that do not support the write-once format. The first generation of DVD+RW PC drives (manufactured before April, 2002) will not record to DVD+R discs. The first generation of DVD+RW video recorders will record to DVD+R discs, but a firmware upgrade will be required. Supporting Companies
The primary supporting companies of the DVD+R (and +RW) format are those that make up the DVD+RW Alliance: Philips, Hewlett Packard, Sony, Yamaha, Ricoh, and Mitsubishi/Verbatim. Dell and Thompson Electronics have recently joined, as well as dozens of other companies that include manufacturers of consumer electronics, recordable media, PC peripherals, and software developers. DVD+R Applications
Since DVD+R is a permanent write-once format, it is well suited for any application that requires archival or high capacity storage Back to top
DVD+RW What is DVD+RW?
DVD+RW is a rewritable / recordable DVD format that has been developed in cooperation by Hewlett-Packard, Mitsubishi Chemical, Philips, Ricoh, Sony, and Yamaha, the primary supporting companies of the DVD+RW Alliance. It currently has a single-sided capacity of 4.7GB and a double-sided capacity of 9.4GB on a 12cm disc. Although DVD+RW is not an approved format of the DVD Forum, it is gaining popularity due to it's claim that it is the only re-writable DVD format that provides full compatibility with existing DVD-Video players and DVD-ROM drives. How does DVD+RW work?
DVD+RW, like its rewritable competitors DVD-RAM and DVD-RW, utilizes phase change material to record information to the disc. The recording laser heats the phase change surface, thereby changing the material's reflective properties between a crystalline (highly reflective) and an amorphous (dull, non-reflective) state. The resulting light and dark spots can be optically distinguished and thereby interpreted as data bits by the computer or video player. DVD+RW's phase change recording layer can be re-written over 1,000 times without media degradation. The estimated life of a DVD+RW disc is 30 to 100 years. The DVD+RW Recording Format
The DVD+RW format can record either sequentially or randomly because it supports both CAV (Constant Angular Velocity) and CLV (Constant Linear Velocity) recording. With CAV recording, the speed of the disc remains constant, regardless of where the data is physically being recorded to the disc. This constant rotation speed of the disc enables fast random access, making DVD+RW suitable for random data recording. With CLV recording, the speed of the disc decreases as data is being written to it. The data is written to the disc in a spiral fashion, beginning at the center hub and spiraling outward towards the edge of the disc. By slowing the rotation speed of the disc as the data is being written to it further and further from the center, a constant data transfer rate is maintained. This constant transfer rate makes DVD+RW perfectly suited for real-time video recording, too. Additional features of the DVD+RW recording format include: - No finalization required - DVD+RW discs do not need to be finalized to make them compatible with DVD-Video players. While recording, the process can be stopped at any time and the disc can be removed and played in a DVD-Video player.
- Lossless Linking - In the DVD+RW Video format, recording is done at a constant bit rate, therefore it needs to be paused and continued frequently. This would normally result in a "linking loss" between the points where the recording stopped and where it resumed, and this linking loss could create a problem during playback. The reader or player would not be able to seamlessly bridge (or "link") the gap between those two points, making the disc incompatible with read-only devices like DVD-Video players and DVD-ROM drives. With it's "lossless linking" technology, DVD+RW is the only rewritable DVD format that is capable of pausing and resuming the recording process without any linking loss. This feature is not only an advantage for random data recording, but it also makes the format very suitable for video applications. Due to lossless linking, discs can be edited without having to re-record the entire content. Pieces can be added or deleted with absolutely no linking loss.
- Defect Management - DVD+RW supports a defect management system where the error correction is handled by the recorder, and is 100% invisible to existing drives or players to ensure playback or read compatibility.
- Quick formatting - Enables the instant use of blank discs.
- UDF File Handling - DVD+RW supports the Universal Disc Format, allowing drag-and-drop operations, and making DVD+RW systems highly compatible with CD-based systems.
- 1x-2.4x Recording - DVD+RW records at 1x - 2.4x DVD-Video data rates, or 11-26Mbs.
Compatibility
DVD+RW is designed to be compatible with computer DVD-ROM drives and consumer DVD-Video players. This "2-way compatibility" ensures that a DVD+RW disc will play back in both DVD-Video players and computer DVD-ROM drives (as long as they have MPEG-2 decoding capabilities), regardless of which type of drive it was recorded in. Once a DVD+RW disc has been recorded, its characteristics comply with the specifications for DVD-ROM, ensuring compatibility across all platforms. DVD+RW Applications
Sequential recording is preferred for video/multi-media applications, where random access, because of its faster data transfer rate, is better suited for data storage applications. Since the DVD+RW format is capable of recording both sequentially and randomly, it is perfectly suited for both data and video/multi-media applications. It should be noted that DVD's that are protected with CSS (Content Scrambling System) protection cannot be duplicated onto DVD+RW media. Back to top
DVD-RAM What is DVD-RAM?
DVD-RAM is a high-performance, rewritable/recordable, optical disc that enables information to be read, written, erased and re-written again. It acts similar to a floppy disc, where programs can be run from it, data can be stored, or files can be written and deleted. Current DVD-RAM capacity is 4.7GB for a single sided disc and 9.4GB for a double-sided disc. First generation capacity was 2.6GB for a single sided disc and 5.2GB for a double-sided disc. DVD-RAM drives feature backward read compatibility with all CD formats and enhanced durability (100,000 re-write cycles and a 30 + year life span). Double-sided RAM discs can hold more than 14 times that of a standard CD-R. DVD-RAM is the format of choice for such manufacturers as Hitachi, Panasonic and Toshiba. What are the different types of DVD-RAM?
There are two types of DVD-RAM cartridges: Type 1 is double sided and Type 2 is single sided. Type 2 cartridges can be removed from their cartridges and Type 1 discs are sealed in the cartridge and are not removable. Single sided DVD-RAM discs, when removed from their cartridge, can be read in current DVD-RAM consumer players and computer DVD ROM drives. Double-sided discs are not removable from their cartridges and can only be played back or written in cartridge compatible drives and players. How does DVD-RAM work?
DVD-RAM is different than DVD-R in that it uses re-writable phase change material rather than the write-once organic dye material that comprises a DVD-R and a CD-R. When writing, a laser heats the phase change material in the disc to about 900-1300F, changing its reflective properties from shiny to dull. If the disc needs to be erased, a laser heats the disc again to about 400F to return the disc to its original shiny state. A laser of lesser power is used to read the written marks. These shiny and dull marks represent data to a computer. They are then interpreted by the computer and then translated into usable information. Second Generation 4.7GB (single sided) and 9.4 (double sided) DVD-RAM achieve their higher capacities by decreasing track width and laser spot size. What are the differences between DVD-RAM and the other rewritable formats?
First, DVD-RAM media is random access like a hard disk. This enables DVD-RAM to retrieve data faster then the other available formats (current DVD-RAM transfer rate is 22.16Mbps). Secondly, DVD-RAM is more robust than it's competition. It is rated at 100,000 rewrites, while DVD RW and DVD+RW specify approximatly1000 rewrites. DVD-RAM has 9 internal recording surfaces as compared to 3 internal recording surfaces for DVD-RW and DVD+RW. DVD-RAM's metal alloy was created for computer use and therefore affords RAM a far greater number of rewrites. RAM also boasts a sophisticated ECC error correction scheme that makes it ideal for data applications. What applications is DVD-RAM best suited for?
DVD-RAM's durability and high number of rewrites make it the perfect solution for multifunction jukeboxes providing high capacity, on line storage for document imaging and full motion video. Because of DVD-RAM's speed and error correction technology, these discs are also suited for backup and archiving. DVD-RAM also provides videographers with a solution for storing DV and analog productions instead of hard disc or videotape. By using removable DVD-RAM for mastering and archiving instead of space limited hard drives or poor quality VHS tape, users will achieve the highest quality possible and gain added flexibility. RAM is also well suited for the medical or legal industries. DVD-RAM is currently being utilized in hospitals and radiology labs to store X-rays, CAT scans and other large image files. This provides medical professionals with a reliable, low-cost means of storing test results digitally so they can be easily accessed and shared with others. What is a DVD-RAM camcorder disc?
DVD-RAM video camcorder disc is a mini sized DVD (8cm) with a recording capacity of 30 minutes. A standard sized DVD-RAM disc is 12 cm and has a recording capacity of 120 minutes using standard quality recording. These mini DVD-RAM discs are used in Hitachi's new DVD-RAM camcorder and can be played back in Hitachi, Panasonic, Toshiba and several other brands of DVD video players. Back to top |
