DVD Technical Data

Maximum Running Time for DVD Video:
90 Minutes is a reasonable rule of thumb for a DVD5, and approximately twice that on a DVD9. But it's a flexible format - which needs a little explanation...

The DVD Video format was developed by a consortium of film studios and hardware manufacturers as a medium for rental and sell-through feature films, to replace the VHS tape cassette. The idea was that a single sided, single layer disc (DVD5) should be capable of holding a 90 minute film, encoded at broadcast video quality, together with full surround soundtrack in 4 or 5 different languages, with subtiltles in those languages, plus facilities for different camera angles, regional coding, parental control, etc.

The main factor affecting running time is the video compression bit-rate used during the MPEG2 encoding...

• Higher bit-rate = higher video quality = more disc space needed = shorter playing time
• Lower bit-rate = lower video quality = less disc space needed = longer playing time
• Variable bit-rate = less disc space than constant bit-rate video of equal quality = longer playing time than constant bit-rate equivalent

DVD9 is a single-sided, dual layer disc format. These discs have approximately twice the capacity of DVD5, but are more costly to author and manufacture. During playback, the DVD player plays through the first layer, then at the end the laser refocuses onto the second layer and continues playback. The viewer may notice a slight pause at that point.

We can manufacture pressed runs of DVD9, but not short-run duplicated runs at present.

Maximum Amount Of Data For DVD-ROM:
4.7 gigabytes on DVD5
8.5 gigabytes on DVD9

Region Coding
Most commercial releases are encoded with a Region Code. When the DVD format was being devised, the world was divided into several regions, each allocated a number, (for example USA & Canada are Region 1, and Europe & Japan are Region 2). DVD players to be sold in each global region are encoded with the appropriate Region number. The DVD discs to be sold in that region are also encoded with the same Region number. If the number on the disc is the same as that on the player it plays - if not, it doesn't play. The idea is to prevent discs from one region, where the film is already on release, being played in a region where the film is not yet released. Control of grey imports is another factor.

However, we find that most of our customers are not affected by these factors. Consequently, most of the discs we manufacture have no Region Coding. This is indicated on the packaging as Region 0 - which basically means the disc will play in any player (subject to video compatability issues. See PAL/NTSC below!)

The whole situation has now been further blurred by the availability of 'Region-free' players, which can theoretically play any disc (subject to video compatability issues. See PAL/NTSC below!).

PAL vs NTSC
A DVD can be either PAL or NTSC but not both.

PAL is the video standard used in the UK and most of Europe, so if your potential viewers are exclusively in these areas, then PAL is the best format to use for your DVD.

DVDs destined to be played on DVD Players (as opposed to on a computer) in the USA or Japan should use the NTSC video standard. It is considered inferior in picture quality to PAL, but there's no alternative, as hardly any DVD players in the US are able to play a PAL disc. Strangely, the reverse is not true - most UK and European DVD players will play NTSC discs as well as PAL. So NTSC is a good option if you want your discs to be compatible with players in both the US and Europe.

When playing video DVDs on computers, the situation is slightly different in that the computer doesn't care whether the disc is NTSC or PAL. The issue with computers is more to do with the Region Coding on the disc being compatible with that of the drive in the computer. Therefore, any DVD disc with Region 0 Coding should, theoretically, play in any computer (assuming the computer has a DVD (or BluRay) drive and appropriate DVD Player software).

We can convert PAL to NTSC and vice versa, with very good results. However, this should be done on the uncompressed video, before the MPEG encoding is done.

The audio format for both PAL and NTSC discs can be either PCM or Dolby Digital. PAL discs can additionally use MPEG2 encoded audio.

Aspect Ratio
This term relates to the ‘shape’ of the picture. The two main options are 4.3 (the traditional format) or 16.9 (widescreen). These can be mixed on one disc, but it is not recommended as it doubles the amount of Menus required and can sometimes look awkward.

Artwork Formats For Packaging:
Our prices assume that you are supplying press-ready PDF/X-1a files. These must conform to our dimensions and specifications, available from our office, or click here to download. We have a fully comprehensive artwork and repro department, so we can design your packaging from scratch, or prepare press-ready CTP files from artwork that you may have on disc already. Click here for fmore about our graphics services.

Notes on Providing Masters for DVD Pressing

Master Formats for Pressed DVD Video:
DVD 5 - DLT Tape or DVD-R (or+R)
DVD 9 - 2 DLT Tapes or 2 DVD-R/+Rs (phone us first, as these discs need to be supplied in a specificl format).

Our prices assume that you are supplying a master ready for glass-mastering in one of these formats. If that's a problem, then we have a fully equipped video studio for DVD Authoring, MPEG encoding, editing, transfers, etc. Click here for information.

CSS (Content Scramble System):
This is the official digital encryption scheme used on DVD Video. For DVD pressing jobs, please do NOT encrypt your masters with CSS copy protection . If you need CSS, then it must be applied during glass-mastering at the plant.

DVD-ROM Master Format:
DVD-R (or +R) recorded exactly as the required finished product. Make sure it is fully tested and works in the way you require. Other formats may be acceptable subject to extra charges. Please phone for a quote.

Glass Mastering:
Glass Mastering has to be carried out on every new DVD job. In this process, a glass disc is laser-etched with the information from the master. From this disc the metal stamper is made from which the DVDs are pressed. The Glass Master is actually destroyed during this process and it is the stamper that is stored for future use.

Notes on Providing Masters for DVD Duplication

• Masters must be provided as a DVD disc exactly as you want the finished product to be. Please note: we can currently only duplicate DVD5 discs. (Although it is now possible to burn double layer discs on one's computer, the duplication technology has yet to catch up!)
• Please provide masters for duplication on write-once DVD-R media (not rewritable). We can accept masters on DVD+R, but the discs produced will be DVD-R.
• Please make sure that the disc's playing surface is free from scratches, finger marks or any other damage
• Master discs should be finalised. This applies especially to discs recorded in domestic DVD recorders.
• Please Note: In order for a DVD-ROM to "Autorun" it must contain an Autorun file. If you don't include this on your master then the copies will not Autorun. However, you can ask us to add an Autorun file onto your master, subject to an extra Authoring charge

Video Encoding & Transfer

Our video studio provides top-quality hardware encoding into variable bit-rate MPEG 2 for DVD Video, or high quality MPEG 1 for desktop Video on CD applications.

We have technicians and a fully equipped studio to meet your requirements for transfers and format conversions...

Tape Formats:

• HDV
• Digi Beta
• Betacam SP
• DV Cam
• Mini DV
• 8mm
• S-VHS
• VHS

File Formats:

• AVI
• Quick Time
• MPEG 2
• MPEG 1
• Real Video
• Windows Media