DVD Overview	DVD (Digital Versatile Disc) picks up where CD left off. Where CDs have a typical storage capacity of 650Mb, DVDs can store between 4.7Gb and 17.1Gb depending on type. This increased capacity has initially been utilised by the film industry as the next generation video format. DVDs have a number of advantages over videotape: Enhanced Durability - No wear from playing, resistant to heat & magnetic fields and cost of manufacture. In addition DVD-Video allows for multiple sound tracks, subtitles, menus, copy protection and 'region codes'. A Region Code added at the authoring stage allows a publisher to limit the number of players a disc will pay on. This works in conjunction with a code in DVD players relating to the geographic region in which they are sold. DVDs can be coded to play on all players.
NTSC v PAL	TV's around the world broadly use 2 mutually incompatible systems, NTSC and PAL. This has created two types of DVDs, as discs are encoded specifically for one or other system. The problem arises in playback of DVDs in home DVD players. All players found in PAL countries will play both disc types. However, NTSC players will only play NTSC discs. This problem exists irrespective of region encoding and as a result appears to be making NTSC the industry standard in terms of the global market.
Versatile	DVD really is versatile, and as a result comes in a number of formats: DVD-Video - The current mainstay of the format. DVD-ROM - Equates to CD-ROM. DVD-Audio - Equates to Music CDs. Hybrid DVD (enhanced DVD) - Plays on home DVD and Computer players, mixing video and data. Cross Platform DVD-ROM - Mixes Apple Mac and PC data / file systems. AV-DVD (Universal DVD) - A a disk that mixes DVD-Video and DVD-Audio. Legacy DVDs - Discs with 2 layers, one of which can be read in a standard CD player. 80mm / 8cm DVDs - Equates to CD Single or Mini CDs. In addition we expect that our 'CD Different' options will become available for CDs in the near future.
Size	DVD discs come in 4 capacities, DVD 5 - 4.7 Gb, single side / single layer. DVD 9 - 8.5 GB, single side / dual layer. DVD 10 - 9.4 GB, double side / single layer. DVD 18 - 17.1 GB, double side / dual layer. Physically DVDs are the same size and thickness as CDs. However as with CDs, each manufacturer is likely to have their own moulds and different label print specifications. DVDs may have 2 data layers, hence single & dual layer discs, and this can be repeated on both sides of the disc, hence the double sided option. Label print on double sided DVDs is restricted to inside the stacking-ring so as not to interfere with the data. The amount of DVD-Video that will fit on any given DVD will depend on the quality of the encoding. A lower quality of encoding will give a longer running time, so you will fit more video encoded with Mpeg 1 than with Mpeg 2. As a general rule of thumb allow about 2 GB per hour for Video, or 2 hours per DVD layer. In the case of ROM applications using DVD 9 it is possible to optimise the disk at the glass mastering stage in order to minimise access times. As a point of interest DVDs are constructed from 2 bonded .06mm substrates (i.e. 2 thin disks glued together!), so a DVD 11 is essentially two DVD 9's back to back. Currently DVD 5 and DVD 9 are in mainstream use.
DVD-R (Recordable)	There are 2 types of Recordable DVD. DVD-R 'Authoring' writers used with special media allow DVD-Video copy protection to be written. Media and Writers are much more expensive then DVD-R 'General', which does not allow copy protected DVD-Video to be produced. Future DVD Recordable formats include DVD+R/W (Re Writable) and DVD-R/W. At the moment the +R and +RW formats are likely to be used in home recorders which will mimic Video Recorders. Microsoft is allegedly adding support for +R & +RW writers to allow for 'drag and drop' authoring. There is likely to be a repeat of the Betamax v VHS format 'war' between +R / +RW and -R / -RW formats for market domination.
DVD-RAM	DVD-RAM is widely used in the design industry as a back-up medium, but it is not widely compatible with home DVD or computer ROM players. This is mainly because of the sensitive nature of the media, which requires a 'caddy' system for protection. DVD-RAM is not a suitable mastering medium for DVD-Video or DVD-ROM.
Authoring	With Apple shipping Macs and iMacs with its 'Super Drive', iDVD and idvd Pro, DVD authoring is a realistic proposition for everyone. If you are planning to have short runs of DVDs copied then a DVD-R will be a acceptable master. If you are planning to produce a larger volume of DVDs, (the break point is currently about 250 DVDs) then you will need to supply a DLT tape master. We can accept a DVD-R but will need to make a charge for converting it to DLT. Please see our DVD mastering page for full details.
Manufacture	DVDs are produced in much the same way as CDs. For small runs we utilise DVD-R media copied from your DVD-R master. DVD-R media can be printed in the same way as CDs. For bigger runs we would 'Press' your DVDs. The pressing process is much the same as CDs in that your master, a DLT tape, is subjected to a 'Glass Mastering' process which produces the mould used to make your finished DVDs, which are then screen printed.
Licensing	Depending on the features and software used on your DVD you may incur royalty fee's. Examples may include but are not limited to Mpeg and MP3. We recommend double checking the terms of your licence(s) before production.
Packaging	DVDs can utilise all the CD packaging types. In addition new packaging for DVD is entering the market. The most popular is a smaller than A5 sized black plastic case, which accepts a cover sheet and booklet. An alternative option is the 'super' Jewel Case, a slightly larger and heavier version of the standard CD Jewel Case.