DVD Guide Glossary
CBR stands for Constant Bit Rate. Bit rate means the amount of data per second. This compression scheme always encodes video or other data at the same bit rate (same data amount per second).
VBR stands for Variable Bit Rate. This scheme encodes at a varying bit rate according to the amount of input video or other data. Generally, VBR retains better quality than CBR if encoding the same amount of data.
Scheme to prohibit copying of copyrighted works. There are two kinds of copy guards for DVDs: analog copy guard for copying to an analog device (such as a VCR), and digital copy guard for copying to another digital device.
Scheme to restrict copying of copyrighted works. There are “Copy-Never” signals that prohibit copying entirely, “Copy-Once” signals that allow copying only once, and “Copy-Free” signals that allow copying without limitation.
CPRM (Content Protection for Recordable Media) is copyright protection technology for recording “Copy-Once” programs of digital broadcasts (terrestrial and satellite). Such programs are recordable only on CPRM-compatible DVD-RW Ver.1.1/ 1.2, DVD-R for General Ver.2.0/ 2.1, and DVD-RAM for General Ver.2.1 discs, and cannot be recorded on DVD-RW Ver.1.0 or non-conforming Ver.1.1 discs. You can play discs recorded with “Copy-Once” programs on CPRM-compatible DVD devices.
The process of decompressing and converting encoded data into audio and video signals.
The process required to make a disc recordable. Any previously recorded content on the disc is erased in the process.
Acronym for Digital Versatile Disc, which records at a higher density compared to CDs.
Name of the industry association that formulates and promotes the DVD+RW/+R format. Click here for details (English only).
The following are the Write-Once DVD formats:
DVD-R (Recordable)
Max. number of times a disc can be recorded: 1
Data capacity1: 4.7 GB
DVD-R was officially approved by the DVD Forum as a “Write-Once” format, and allows recording only once like CD-R. Since DVD-R format was originally created to make a master disc or sample verification disc in developing DVD-ROM and DVD VIDEO, it has similar high compatibility characteristics.
The data capacity for DVD-R Ver.2.0 (approved May 2000 as an authoring format, and February as a general format) or later versions is specified as 4.7 GB, which is the same as the rewritable DVD formats.
11 GB (Gigabyte) represents 1,000,000,000 bytes in all instances.
DVD+R (+Recordable)
Max. number of times a disc can be recorded: 1
Data capacity1: 4.7 GB
Based on the DVD+RW format, the DVD+RW Alliance formulated DVD+R in January 2002 as a Write-Once format for the long-term storage of important data, since it does not allow for overwriting (such as accidental erasure).
Its disc face is more reflective than DVD+RW, resulting in higher playback compatibility with existing devices.
11 GB (Gigabyte) represents 1,000,000,000 bytes in all instances.
The following are the Rewritable DVD formats:
DVD-RW (Re-recordable)
Max. number of times a disc can be recorded: 1,000 (approx.)
Data capacity1: 4.7 GB (single-sided) / 9.4 GB (double-sided)
DVD-RW is the rewritable version of Write-Once DVD-Rs and is approved by the DVD Forum. DVD-RW has a similar physical format to read-only DVDs and features two recording formats: DVD Video recording and DVD Video (or VR mode and Video mode).
The DVD Video Recording format was included in the initial Ver.1.0 specifications, and in March 2000, the DVD Video format that allows for playback on DVD players was included in Ver.1.1.
Furthermore, CPRM-compatible DVD-RW Ver.1.1 can record TV programs that contain CPRM signals2.
A DVD-RW can be rewritten approximately 1,000 times.
11 GB (Gigabyte) represents 1,000,000,000 bytes in all instances.
2will not play on other DVD players, or DVD recorders not conforming to CPRM.
DVD+RW (+Re-Writable)
Max. number of times a disc can be recorded: 1,000x (approx).
Data capacity1: 4.7 GB
DVD+RW was made public by the DVD+RW Alliance (formed by eight manufactures2 that promote CD-RW/ -R media and drives in October 1999, and is a rewritable DVD format.
The DVD+RW format aims for playback compatibility with the existing DVD-ROM drives and DVD players, and random read/write accessibility for data storage on PCs. Rewrite is allowed about 1,000 times.
11 GB (Gigabyte) represents 1,000,000,000 bytes in all instances.
2Dell, Hewlett-Packard, Mitsubishi Chemical, Philips, Ricoh, THOMSON Multimedia, YAMAHA and Sony.
DVD-RAM (Rewritable)
Max. number of times a disc can be recorded: 100,000x (approx).
Data capacity1: 4.7 GB (single-sided)/ 9.4 GB (double-sided)
DVD-RAM is a format approved by the DVD Forum. When Ver.1.0 was released in July 1997, it was a single-sided disc of 2.6 GB, mounted in a protective cartridge. Later in September 1999, Ver.2.0 was released with capacity of 4.7 GB for single-sided discs, and 9.4 GB for double-sided discs.
DVD-RAM’s compatibility with existing DVD-ROM drives and DVD players is low, while its PC data storage feature is enhanced (e.g., number of times you can rewrite, etc.).
11 GB (Gigabyte) represents 1,000,000,000 bytes in all instances.
The following is the Read-only DVD formats:
DVD-ROM (read-only memory)
Max. number of times a disc can be recorded: None.
Data capacity1: 4.7 GB
DVD-ROM is a read-only DVD, and is the equivalent of a CD-ROM among CDs. DVD-ROM discs are widely used for distribution of PC software or video contents such as movies.
11 GB (Gigabyte) represents 1,000,000,000 bytes in all instances.
For compatible products, please click here (go to Recording Compatibility Table)
A 12-cm video disc that contains audio and video using MPEG 2 for moving picture compression. This format is used for sales and distribution of movies and music videos.
DVD Video format (Video mode)
DVD Video format (Video mode) was formulated as the first playback (read-only) application within the DVD family.
Since its purpose was to store an entire movie on one disc retaining quality audio/video, the format was adopted for commercial DVDs and playback devices such as DVD players. MPEG-2 is used for video compression, and Liner PCM, Dolby Digital and others schemes are adopted for audio, reproducing high quality pictures (about 500 TV lines of horizontal definition) and dynamic sound fields.
In addition, interactive functions such as multi-language, multi-story, and multi-angles are also possible.
This playback application for DVD players is now adopted as the recording application for DVD-RWs/-Rs for general DVD recorders.
Since it was originally for DVD players, the main feature of DVD Video format is its high-compatibility with conventional DVD players.
However, a DVD Video disc during the editing stage (not in its final form) is not formatted enough to play on other DVD players. The disc needs to be finalized to format its data according to the DVD Video specifications.
DVD Video Recording format (VR mode)
DVD Video Recording format (VR mode) was established by the DVD Forum for recording moving pictures in real time.
The format is used for DVD-RWs/DVD-Rs/DVD-RAMs, and together with random recording of UDF Ver.2.00 (explained in “Physical Format”), it offers discretional division and arrangement of recorded data. These capabilities made various edits on recorded contents possible, enabling not only the edits on the recorded data itself (original data), but also the virtual edits called Playlists that enable a variety of edits without altering the original data. Furthermore, the format records both language tracks of bilingual broadcasts, retains different aspect ratios within a single title, and records “Copy-Once” copy-controlled contents―features suitable for recording TV programs.
DVD+RW Video format (+VR mode)
DVD+RW Video format (+VR mode) was formulated for recording moving pictures on DVD+RWs, and is also called +VR format.
The format’s main feature is real-time recording, the ability to add recordings, and the overwrite function, while ensuring playback compatibility with conventional DVD players and DVD drives on PCs. The format specifies that finalizing (such as lead-out marking at the data end on the disc) be automatic.
These features allow flexibility for users. The disc is playable on other players immediately after ejecting from the recorder, and you can add recordings by re-inserting the disc into the recorder. Moreover, the recorded contents are allowed simple edits on the same disc.
Name of the association that formulates and promotes DVD formats. Click here for details (English only).
The process of converting and compressing audio and video signals into digital data according to a certain format (e.g. MPEG-2, etc).
Finalizing means making recorded DVD-Rs/-RWs compatible so they play on other playback devices. Without this process, a DVD-R recorded on one manufacturer’s device normally does not play on other manufacturer’s devices. Finalizing ensures that compatibility. Finalizing makes the disc you recorded similar to commercially available “DVD VIDEOs.” The process enables the disc to play on other manufacturer’s devices.
To be specific, the finalizing device adds the disc’s table of contents to the innermost periphery, thereby making it playable on other devices.
Please note that DVD-Rs and DVD+Rs cannot be recorded on (neither audio nor video) further once finalized. With DVD-RWs, you can unfinalize to record on them again.
MPEG stands for Moving Picture Experts Group - a working group set up by ISO (International Organization for Standardization). The group name is now used as one of the video data compression scheme names. MPEG-2 is one of the schemes established by the group, which requires about 4 to 15 Mbps audio/video transport speed.
There are other formats such as MPEG-1 for Video CDs, and MPEG-4 moving picture format for mobile-devices.
RWPPI stands for RW Products Promotion Initiative. An action group whose initiative is to promote the smooth diffusion of recordable DVD products. Click here for details (English only).
A format that allows recording only once. Additional recording is possible, but existing data on a disc cannot be overwritten.
